Merge pull request #759 from matrix-org/dbkr/email_notifs

Send email notifications for missed messages

22 files changed, 1170 insertions, 34 deletions

diff --git a/synapse/app/pusher.py b/synapse/app/pusher.py
index b5339f030d..89c8d5c7ce 100644
--- a/synapse/app/pusher.py
+++ b/synapse/app/pusher.py
@@ -20,6 +20,7 @@ from synapse.server import HomeServer
 from synapse.config._base import ConfigError
 from synapse.config.database import DatabaseConfig
 from synapse.config.logger import LoggingConfig
+from synapse.config.emailconfig import EmailConfig
 from synapse.http.site import SynapseSite
 from synapse.metrics.resource import MetricsResource, METRICS_PREFIX
 from synapse.replication.slave.storage.events import SlavedEventStore
@@ -91,7 +92,7 @@ class SlaveConfig(DatabaseConfig):
         """ % locals()
 
 
-class PusherSlaveConfig(SlaveConfig, LoggingConfig):
+class PusherSlaveConfig(SlaveConfig, LoggingConfig, EmailConfig):
     pass
 
 
@@ -110,6 +111,18 @@ class PusherSlaveStore(
         DataStore.update_pusher_last_stream_ordering.__func__
     )
 
+    get_throttle_params_by_room = (
+        DataStore.get_throttle_params_by_room.__func__
+    )
+
+    set_throttle_params = (
+        DataStore.set_throttle_params.__func__
+    )
+
+    get_time_of_last_push_action_before = (
+        DataStore.get_time_of_last_push_action_before.__func__
+    )
+
 
 class PusherServer(HomeServer):
 
diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
new file mode 100644
index 0000000000..90bdd08f00
--- /dev/null
+++ b/synapse/config/emailconfig.py
@@ -0,0 +1,98 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015, 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This file can't be called email.py because if it is, we cannot:
+import email.utils
+
+from ._base import Config
+
+
+class EmailConfig(Config):
+    def read_config(self, config):
+        self.email_enable_notifs = False
+
+        email_config = config.get("email", {})
+        self.email_enable_notifs = email_config.get("enable_notifs", False)
+
+        if self.email_enable_notifs:
+            # make sure we can import the required deps
+            import jinja2
+            import bleach
+            # prevent unused warnings
+            jinja2
+            bleach
+
+            required = [
+                "smtp_host",
+                "smtp_port",
+                "notif_from",
+                "template_dir",
+                "notif_template_html",
+                "notif_template_text",
+            ]
+
+            missing = []
+            for k in required:
+                if k not in email_config:
+                    missing.append(k)
+
+            if (len(missing) > 0):
+                raise RuntimeError(
+                    "email.enable_notifs is True but required keys are missing: %s" %
+                    (", ".join(["email." + k for k in missing]),)
+                )
+
+            if config.get("public_baseurl") is None:
+                raise RuntimeError(
+                    "email.enable_notifs is True but no public_baseurl is set"
+                )
+
+            self.email_smtp_host = email_config["smtp_host"]
+            self.email_smtp_port = email_config["smtp_port"]
+            self.email_notif_from = email_config["notif_from"]
+            self.email_template_dir = email_config["template_dir"]
+            self.email_notif_template_html = email_config["notif_template_html"]
+            self.email_notif_template_text = email_config["notif_template_text"]
+            self.email_notif_for_new_users = email_config.get(
+                "notif_for_new_users", True
+            )
+            if "app_name" in email_config:
+                self.email_app_name = email_config["app_name"]
+            else:
+                self.email_app_name = "Matrix"
+
+            # make sure it's valid
+            parsed = email.utils.parseaddr(self.email_notif_from)
+            if parsed[1] == '':
+                raise RuntimeError("Invalid notif_from address")
+        else:
+            self.email_enable_notifs = False
+            # Not much point setting defaults for the rest: it would be an
+            # error for them to be used.
+
+    def default_config(self, config_dir_path, server_name, **kwargs):
+        return """
+        # Enable sending emails for notification events
+        #email:
+        #   enable_notifs: false
+        #   smtp_host: "localhost"
+        #   smtp_port: 25
+        #   notif_from: Your Friendly Matrix Home Server <noreply@example.com>
+        #   app_name: Matrix
+        #   template_dir: res/templates
+        #   notif_template_html: notif_mail.html
+        #   notif_template_text: notif_mail.txt
+        #   notif_for_new_users: True
+        """
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index 9a80ac39ec..fc2445484c 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -31,13 +31,14 @@ from .cas import CasConfig
 from .password import PasswordConfig
 from .jwt import JWTConfig
 from .ldap import LDAPConfig
+from .emailconfig import EmailConfig
 
 
 class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
                        RatelimitConfig, ContentRepositoryConfig, CaptchaConfig,
                        VoipConfig, RegistrationConfig, MetricsConfig, ApiConfig,
                        AppServiceConfig, KeyConfig, SAML2Config, CasConfig,
-                       JWTConfig, LDAPConfig, PasswordConfig,):
+                       JWTConfig, LDAPConfig, PasswordConfig, EmailConfig,):
     pass
 
 
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 46c633548a..0b5f462e44 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -28,6 +28,11 @@ class ServerConfig(Config):
         self.print_pidfile = config.get("print_pidfile")
         self.user_agent_suffix = config.get("user_agent_suffix")
         self.use_frozen_dicts = config.get("use_frozen_dicts", True)
+        self.public_baseurl = config.get("public_baseurl")
+
+        if self.public_baseurl is not None:
+            if self.public_baseurl[-1] != '/':
+                self.public_baseurl += '/'
         self.start_pushers = config.get("start_pushers", True)
 
         self.listeners = config.get("listeners", [])
@@ -143,6 +148,9 @@ class ServerConfig(Config):
         # Whether to serve a web client from the HTTP/HTTPS root resource.
         web_client: True
 
+        # The public-facing base URL for the client API (not including _matrix/...)
+        # public_baseurl: https://example.com:8448/
+
         # Set the soft limit on the number of file descriptors synapse can use
         # Zero is used to indicate synapse should set the soft limit to the
         # hard limit.
diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index 745c8901ee..2c811906d9 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -208,7 +208,7 @@ class BaseHandler(object):
         })
 
     @defer.inlineCallbacks
-    def _filter_events_for_client(self, user_id, events, is_peeking=False):
+    def filter_events_for_client(self, user_id, events, is_peeking=False):
         """
         Check which events a user is allowed to see
 
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index f51feda2f4..7d9e3cf364 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -123,7 +123,7 @@ class MessageHandler(BaseHandler):
                 "end": next_token.to_string(),
             })
 
-        events = yield self._filter_events_for_client(
+        events = yield self.filter_events_for_client(
             user_id,
             events,
             is_peeking=(member_event_id is None),
@@ -483,7 +483,7 @@ class MessageHandler(BaseHandler):
                     ]
                 ).addErrback(unwrapFirstError)
 
-                messages = yield self._filter_events_for_client(
+                messages = yield self.filter_events_for_client(
                     user_id, messages
                 )
 
@@ -619,7 +619,7 @@ class MessageHandler(BaseHandler):
             end_token=stream_token
         )
 
-        messages = yield self._filter_events_for_client(
+        messages = yield self.filter_events_for_client(
             user_id, messages, is_peeking=is_peeking
         )
 
@@ -700,7 +700,7 @@ class MessageHandler(BaseHandler):
             consumeErrors=True,
         ).addErrback(unwrapFirstError)
 
-        messages = yield self._filter_events_for_client(
+        messages = yield self.filter_events_for_client(
             user_id, messages, is_peeking=is_peeking,
         )
 
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index dd9c18df84..fdebc9c438 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -449,7 +449,7 @@ class RoomContextHandler(BaseHandler):
         now_token = yield self.hs.get_event_sources().get_current_token()
 
         def filter_evts(events):
-            return self._filter_events_for_client(
+            return self.filter_events_for_client(
                 user.to_string(),
                 events,
                 is_peeking=is_guest)
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index 9937d8dd7f..a937e87408 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -172,7 +172,7 @@ class SearchHandler(BaseHandler):
 
             filtered_events = search_filter.filter([r["event"] for r in results])
 
-            events = yield self._filter_events_for_client(
+            events = yield self.filter_events_for_client(
                 user.to_string(), filtered_events
             )
 
@@ -223,7 +223,7 @@ class SearchHandler(BaseHandler):
                     r["event"] for r in results
                 ])
 
-                events = yield self._filter_events_for_client(
+                events = yield self.filter_events_for_client(
                     user.to_string(), filtered_events
                 )
 
@@ -281,11 +281,11 @@ class SearchHandler(BaseHandler):
                     event.room_id, event.event_id, before_limit, after_limit
                 )
 
-                res["events_before"] = yield self._filter_events_for_client(
+                res["events_before"] = yield self.filter_events_for_client(
                     user.to_string(), res["events_before"]
                 )
 
-                res["events_after"] = yield self._filter_events_for_client(
+                res["events_after"] = yield self.filter_events_for_client(
                     user.to_string(), res["events_after"]
                 )
 
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 0bb1913285..b7dcbc6b1b 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -697,7 +697,7 @@ class SyncHandler(BaseHandler):
 
             if recents is not None:
                 recents = sync_config.filter_collection.filter_room_timeline(recents)
-                recents = yield self._filter_events_for_client(
+                recents = yield self.filter_events_for_client(
                     sync_config.user.to_string(),
                     recents,
                 )
@@ -718,7 +718,7 @@ class SyncHandler(BaseHandler):
                 loaded_recents = sync_config.filter_collection.filter_room_timeline(
                     events
                 )
-                loaded_recents = yield self._filter_events_for_client(
+                loaded_recents = yield self.filter_events_for_client(
                     sync_config.user.to_string(),
                     loaded_recents,
                 )
diff --git a/synapse/notifier.py b/synapse/notifier.py
index 6af7a8f424..cb58dfffd4 100644
--- a/synapse/notifier.py
+++ b/synapse/notifier.py
@@ -399,7 +399,7 @@ class Notifier(object):
 
                 if name == "room":
                     room_member_handler = self.hs.get_handlers().room_member_handler
-                    new_events = yield room_member_handler._filter_events_for_client(
+                    new_events = yield room_member_handler.filter_events_for_client(
                         user.to_string(),
                         new_events,
                         is_peeking=is_peeking,
diff --git a/synapse/push/emailpusher.py b/synapse/push/emailpusher.py
new file mode 100644
index 0000000000..3a13c7485a
--- /dev/null
+++ b/synapse/push/emailpusher.py
@@ -0,0 +1,251 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from twisted.internet import defer, reactor
+
+import logging
+
+from synapse.util.metrics import Measure
+from synapse.util.logcontext import LoggingContext
+
+from mailer import Mailer
+
+logger = logging.getLogger(__name__)
+
+# The amount of time we always wait before ever emailing about a notification
+# (to give the user a chance to respond to other push or notice the window)
+DELAY_BEFORE_MAIL_MS = 2 * 60 * 1000
+
+THROTTLE_START_MS = 2 * 60 * 1000
+THROTTLE_MAX_MS = (2 * 60 * 1000) * (2 ** 11)  # ~3 days
+THROTTLE_MULTIPLIER = 2
+
+# If no event triggers a notification for this long after the previous,
+# the throttle is released.
+THROTTLE_RESET_AFTER_MS = (2 * 60 * 1000) * (2 ** 11)  # ~3 days
+
+
+class EmailPusher(object):
+    """
+    A pusher that sends email notifications about events (approximately)
+    when they happen.
+    This shares quite a bit of code with httpusher: it would be good to
+    factor out the common parts
+    """
+    def __init__(self, hs, pusherdict):
+        self.hs = hs
+        self.store = self.hs.get_datastore()
+        self.clock = self.hs.get_clock()
+        self.pusher_id = pusherdict['id']
+        self.user_id = pusherdict['user_name']
+        self.app_id = pusherdict['app_id']
+        self.email = pusherdict['pushkey']
+        self.last_stream_ordering = pusherdict['last_stream_ordering']
+        self.timed_call = None
+        self.throttle_params = None
+
+        # See httppusher
+        self.max_stream_ordering = None
+
+        self.processing = False
+
+        if self.hs.config.email_enable_notifs:
+            self.mailer = Mailer(self.hs)
+        else:
+            self.mailer = None
+
+    @defer.inlineCallbacks
+    def on_started(self):
+        if self.mailer is not None:
+            self.throttle_params = yield self.store.get_throttle_params_by_room(
+                self.pusher_id
+            )
+            yield self._process()
+
+    def on_stop(self):
+        if self.timed_call:
+            self.timed_call.cancel()
+
+    @defer.inlineCallbacks
+    def on_new_notifications(self, min_stream_ordering, max_stream_ordering):
+        self.max_stream_ordering = max(max_stream_ordering, self.max_stream_ordering)
+        yield self._process()
+
+    def on_new_receipts(self, min_stream_id, max_stream_id):
+        # We could wake up and cancel the timer but there tend to be quite a
+        # lot of read receipts so it's probably less work to just let the
+        # timer fire
+        return defer.succeed(None)
+
+    @defer.inlineCallbacks
+    def on_timer(self):
+        self.timed_call = None
+        yield self._process()
+
+    @defer.inlineCallbacks
+    def _process(self):
+        if self.processing:
+            return
+
+        with LoggingContext("emailpush._process"):
+            with Measure(self.clock, "emailpush._process"):
+                try:
+                    self.processing = True
+                    # if the max ordering changes while we're running _unsafe_process,
+                    # call it again, and so on until we've caught up.
+                    while True:
+                        starting_max_ordering = self.max_stream_ordering
+                        try:
+                            yield self._unsafe_process()
+                        except:
+                            logger.exception("Exception processing notifs")
+                        if self.max_stream_ordering == starting_max_ordering:
+                            break
+                finally:
+                    self.processing = False
+
+    @defer.inlineCallbacks
+    def _unsafe_process(self):
+        """
+        Main logic of the push loop without the wrapper function that sets
+        up logging, measures and guards against multiple instances of it
+        being run.
+        """
+        unprocessed = yield self.store.get_unread_push_actions_for_user_in_range(
+            self.user_id, self.last_stream_ordering, self.max_stream_ordering
+        )
+
+        soonest_due_at = None
+
+        for push_action in unprocessed:
+            received_at = push_action['received_ts']
+            if received_at is None:
+                received_at = 0
+            notif_ready_at = received_at + DELAY_BEFORE_MAIL_MS
+
+            room_ready_at = self.room_ready_to_notify_at(
+                push_action['room_id']
+            )
+
+            should_notify_at = max(notif_ready_at, room_ready_at)
+
+            if should_notify_at < self.clock.time_msec():
+                # one of our notifications is ready for sending, so we send
+                # *one* email updating the user on their notifications,
+                # we then consider all previously outstanding notifications
+                # to be delivered.
+                yield self.send_notification(unprocessed)
+
+                yield self.save_last_stream_ordering_and_success(max([
+                    ea['stream_ordering'] for ea in unprocessed
+                ]))
+                yield self.sent_notif_update_throttle(
+                    push_action['room_id'], push_action
+                )
+                break
+            else:
+                if soonest_due_at is None or should_notify_at < soonest_due_at:
+                    soonest_due_at = should_notify_at
+
+                if self.timed_call is not None:
+                    self.timed_call.cancel()
+                    self.timed_call = None
+
+        if soonest_due_at is not None:
+            self.timed_call = reactor.callLater(
+                self.seconds_until(soonest_due_at), self.on_timer
+            )
+
+    @defer.inlineCallbacks
+    def save_last_stream_ordering_and_success(self, last_stream_ordering):
+        self.last_stream_ordering = last_stream_ordering
+        yield self.store.update_pusher_last_stream_ordering_and_success(
+            self.app_id, self.email, self.user_id,
+            last_stream_ordering, self.clock.time_msec()
+        )
+
+    def seconds_until(self, ts_msec):
+        return (ts_msec - self.clock.time_msec()) / 1000
+
+    def get_room_throttle_ms(self, room_id):
+        if room_id in self.throttle_params:
+            return self.throttle_params[room_id]["throttle_ms"]
+        else:
+            return 0
+
+    def get_room_last_sent_ts(self, room_id):
+        if room_id in self.throttle_params:
+            return self.throttle_params[room_id]["last_sent_ts"]
+        else:
+            return 0
+
+    def room_ready_to_notify_at(self, room_id):
+        """
+        Determines whether throttling should prevent us from sending an email
+        for the given room
+        Returns: True if we should send, False if we should not
+        """
+        last_sent_ts = self.get_room_last_sent_ts(room_id)
+        throttle_ms = self.get_room_throttle_ms(room_id)
+
+        may_send_at = last_sent_ts + throttle_ms
+        return may_send_at
+
+    @defer.inlineCallbacks
+    def sent_notif_update_throttle(self, room_id, notified_push_action):
+        # We have sent a notification, so update the throttle accordingly.
+        # If the event that triggered the notif happened more than
+        # THROTTLE_RESET_AFTER_MS after the previous one that triggered a
+        # notif, we release the throttle. Otherwise, the throttle is increased.
+        time_of_previous_notifs = yield self.store.get_time_of_last_push_action_before(
+            notified_push_action['stream_ordering']
+        )
+
+        time_of_this_notifs = notified_push_action['received_ts']
+
+        if time_of_previous_notifs is not None and time_of_this_notifs is not None:
+            gap = time_of_this_notifs - time_of_previous_notifs
+        else:
+            # if we don't know the arrival time of one of the notifs (it was not
+            # stored prior to email notification code) then assume a gap of
+            # zero which will just not reset the throttle
+            gap = 0
+
+        current_throttle_ms = self.get_room_throttle_ms(room_id)
+
+        if gap > THROTTLE_RESET_AFTER_MS:
+            new_throttle_ms = THROTTLE_START_MS
+        else:
+            if current_throttle_ms == 0:
+                new_throttle_ms = THROTTLE_START_MS
+            else:
+                new_throttle_ms = min(
+                    current_throttle_ms * THROTTLE_MULTIPLIER,
+                    THROTTLE_MAX_MS
+                )
+        self.throttle_params[room_id] = {
+            "last_sent_ts": self.clock.time_msec(),
+            "throttle_ms": new_throttle_ms
+        }
+        yield self.store.set_throttle_params(
+            self.pusher_id, room_id, self.throttle_params[room_id]
+        )
+
+    @defer.inlineCallbacks
+    def send_notification(self, push_actions):
+        logger.info("Sending notif email for user %r", self.user_id)
+        yield self.mailer.send_notification_mail(
+            self.user_id, self.email, push_actions
+        )
diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
new file mode 100644
index 0000000000..7031fa6d55
--- /dev/null
+++ b/synapse/push/mailer.py
@@ -0,0 +1,455 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from twisted.internet import defer
+from twisted.mail.smtp import sendmail
+
+import email.utils
+import email.mime.multipart
+from email.mime.text import MIMEText
+from email.mime.multipart import MIMEMultipart
+
+from synapse.util.async import concurrently_execute
+from synapse.util.presentable_names import (
+    calculate_room_name, name_from_member_event, descriptor_from_member_events
+)
+from synapse.types import UserID
+from synapse.api.errors import StoreError
+from synapse.api.constants import EventTypes
+
+import jinja2
+import bleach
+
+import time
+import urllib
+
+import logging
+logger = logging.getLogger(__name__)
+
+
+MESSAGE_FROM_PERSON_IN_ROOM = "You have a message on %(app)s from %(person)s " \
+                              "in the %s room..."
+MESSAGE_FROM_PERSON = "You have a message on %(app)s from %(person)s..."
+MESSAGES_FROM_PERSON = "You have messages on %(app)s from %(person)s..."
+MESSAGES_IN_ROOM = "There are some messages on %(app)s for you in the %(room)s room..."
+MESSAGES_IN_ROOMS = "Here are some messages on %(app)s you may have missed..."
+INVITE_FROM_PERSON_TO_ROOM = "%(person)s has invited you to join the " \
+                             "%(room)s room on %(app)s..."
+INVITE_FROM_PERSON = "%(person)s has invited you to chat on %(app)s..."
+
+CONTEXT_BEFORE = 1
+CONTEXT_AFTER = 1
+
+# From https://github.com/matrix-org/matrix-react-sdk/blob/master/src/HtmlUtils.js
+ALLOWED_TAGS = [
+    'font',  # custom to matrix for IRC-style font coloring
+    'del',  # for markdown
+    # deliberately no h1/h2 to stop people shouting.
+    'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
+    'nl', 'li', 'b', 'i', 'u', 'strong', 'em', 'strike', 'code', 'hr', 'br', 'div',
+    'table', 'thead', 'caption', 'tbody', 'tr', 'th', 'td', 'pre'
+]
+ALLOWED_ATTRS = {
+    # custom ones first:
+    "font": ["color"],  # custom to matrix
+    "a": ["href", "name", "target"],  # remote target: custom to matrix
+    # We don't currently allow img itself by default, but this
+    # would make sense if we did
+    "img": ["src"],
+}
+# When bleach release a version with this option, we can specify schemes
+# ALLOWED_SCHEMES = ["http", "https", "ftp", "mailto"]
+
+
+class Mailer(object):
+    def __init__(self, hs):
+        self.hs = hs
+        self.store = self.hs.get_datastore()
+        self.state_handler = self.hs.get_state_handler()
+        loader = jinja2.FileSystemLoader(self.hs.config.email_template_dir)
+        self.app_name = self.hs.config.email_app_name
+        env = jinja2.Environment(loader=loader)
+        env.filters["format_ts"] = format_ts_filter
+        env.filters["mxc_to_http"] = self.mxc_to_http_filter
+        self.notif_template_html = env.get_template(
+            self.hs.config.email_notif_template_html
+        )
+        self.notif_template_text = env.get_template(
+            self.hs.config.email_notif_template_text
+        )
+
+    @defer.inlineCallbacks
+    def send_notification_mail(self, user_id, email_address, push_actions):
+        raw_from = email.utils.parseaddr(self.hs.config.email_notif_from)[1]
+        raw_to = email.utils.parseaddr(email_address)[1]
+
+        if raw_to == '':
+            raise RuntimeError("Invalid 'to' address")
+
+        rooms_in_order = deduped_ordered_list(
+            [pa['room_id'] for pa in push_actions]
+        )
+
+        notif_events = yield self.store.get_events(
+            [pa['event_id'] for pa in push_actions]
+        )
+
+        notifs_by_room = {}
+        for pa in push_actions:
+            notifs_by_room.setdefault(pa["room_id"], []).append(pa)
+
+        # collect the current state for all the rooms in which we have
+        # notifications
+        state_by_room = {}
+
+        try:
+            user_display_name = yield self.store.get_profile_displayname(
+                UserID.from_string(user_id).localpart
+            )
+        except StoreError:
+            user_display_name = user_id
+
+        @defer.inlineCallbacks
+        def _fetch_room_state(room_id):
+            room_state = yield self.state_handler.get_current_state(room_id)
+            state_by_room[room_id] = room_state
+
+        # Run at most 3 of these at once: sync does 10 at a time but email
+        # notifs are much realtime than sync so we can afford to wait a bit.
+        yield concurrently_execute(_fetch_room_state, rooms_in_order, 3)
+
+        rooms = []
+
+        for r in rooms_in_order:
+            roomvars = yield self.get_room_vars(
+                r, user_id, notifs_by_room[r], notif_events, state_by_room[r]
+            )
+            rooms.append(roomvars)
+
+        summary_text = self.make_summary_text(
+            notifs_by_room, state_by_room, notif_events, user_id
+        )
+
+        template_vars = {
+            "user_display_name": user_display_name,
+            "unsubscribe_link": self.make_unsubscribe_link(),
+            "summary_text": summary_text,
+            "app_name": self.app_name,
+            "rooms": rooms,
+        }
+
+        html_text = self.notif_template_html.render(**template_vars)
+        html_part = MIMEText(html_text, "html", "utf8")
+
+        plain_text = self.notif_template_text.render(**template_vars)
+        text_part = MIMEText(plain_text, "plain", "utf8")
+
+        multipart_msg = MIMEMultipart('alternative')
+        multipart_msg['Subject'] = "[%s] %s" % (self.app_name, summary_text)
+        multipart_msg['From'] = self.hs.config.email_notif_from
+        multipart_msg['To'] = email_address
+        multipart_msg['Date'] = email.utils.formatdate()
+        multipart_msg['Message-ID'] = email.utils.make_msgid()
+        multipart_msg.attach(text_part)
+        multipart_msg.attach(html_part)
+
+        logger.info("Sending email push notification to %s" % email_address)
+        # logger.debug(html_text)
+
+        yield sendmail(
+            self.hs.config.email_smtp_host,
+            raw_from, raw_to, multipart_msg.as_string(),
+            port=self.hs.config.email_smtp_port
+        )
+
+    @defer.inlineCallbacks
+    def get_room_vars(self, room_id, user_id, notifs, notif_events, room_state):
+        my_member_event = room_state[("m.room.member", user_id)]
+        is_invite = my_member_event.content["membership"] == "invite"
+
+        room_vars = {
+            "title": calculate_room_name(room_state, user_id),
+            "hash": string_ordinal_total(room_id),  # See sender avatar hash
+            "notifs": [],
+            "invite": is_invite,
+            "link": self.make_room_link(room_id),
+        }
+
+        if not is_invite:
+            for n in notifs:
+                notifvars = yield self.get_notif_vars(
+                    n, user_id, notif_events[n['event_id']], room_state
+                )
+
+                # merge overlapping notifs together.
+                # relies on the notifs being in chronological order.
+                merge = False
+                if room_vars['notifs'] and 'messages' in room_vars['notifs'][-1]:
+                    prev_messages = room_vars['notifs'][-1]['messages']
+                    for message in notifvars['messages']:
+                        pm = filter(lambda pm: pm['id'] == message['id'], prev_messages)
+                        if pm:
+                            if not message["is_historical"]:
+                                pm[0]["is_historical"] = False
+                            merge = True
+                        elif merge:
+                            # we're merging, so append any remaining messages
+                            # in this notif to the previous one
+                            prev_messages.append(message)
+
+                if not merge:
+                    room_vars['notifs'].append(notifvars)
+
+        defer.returnValue(room_vars)
+
+    @defer.inlineCallbacks
+    def get_notif_vars(self, notif, user_id, notif_event, room_state):
+        results = yield self.store.get_events_around(
+            notif['room_id'], notif['event_id'],
+            before_limit=CONTEXT_BEFORE, after_limit=CONTEXT_AFTER
+        )
+
+        ret = {
+            "link": self.make_notif_link(notif),
+            "ts": notif['received_ts'],
+            "messages": [],
+        }
+
+        handler = self.hs.get_handlers().message_handler
+        the_events = yield handler.filter_events_for_client(
+            user_id, results["events_before"]
+        )
+        the_events.append(notif_event)
+
+        for event in the_events:
+            messagevars = self.get_message_vars(notif, event, room_state)
+            if messagevars is not None:
+                ret['messages'].append(messagevars)
+
+        defer.returnValue(ret)
+
+    def get_message_vars(self, notif, event, room_state):
+        if event.type != EventTypes.Message:
+            return None
+
+        sender_state_event = room_state[("m.room.member", event.sender)]
+        sender_name = name_from_member_event(sender_state_event)
+        sender_avatar_url = sender_state_event.content["avatar_url"]
+
+        # 'hash' for deterministically picking default images: use
+        # sender_hash % the number of default images to choose from
+        sender_hash = string_ordinal_total(event.sender)
+
+        ret = {
+            "msgtype": event.content["msgtype"],
+            "is_historical": event.event_id != notif['event_id'],
+            "id": event.event_id,
+            "ts": event.origin_server_ts,
+            "sender_name": sender_name,
+            "sender_avatar_url": sender_avatar_url,
+            "sender_hash": sender_hash,
+        }
+
+        if event.content["msgtype"] == "m.text":
+            self.add_text_message_vars(ret, event)
+        elif event.content["msgtype"] == "m.image":
+            self.add_image_message_vars(ret, event)
+
+        if "body" in event.content:
+            ret["body_text_plain"] = event.content["body"]
+
+        return ret
+
+    def add_text_message_vars(self, messagevars, event):
+        if "format" in event.content:
+            msgformat = event.content["format"]
+        else:
+            msgformat = None
+        messagevars["format"] = msgformat
+
+        if msgformat == "org.matrix.custom.html":
+            messagevars["body_text_html"] = safe_markup(event.content["formatted_body"])
+        else:
+            messagevars["body_text_html"] = safe_text(event.content["body"])
+
+        return messagevars
+
+    def add_image_message_vars(self, messagevars, event):
+        messagevars["image_url"] = event.content["url"]
+
+        return messagevars
+
+    def make_summary_text(self, notifs_by_room, state_by_room, notif_events, user_id):
+        if len(notifs_by_room) == 1:
+            # Only one room has new stuff
+            room_id = notifs_by_room.keys()[0]
+
+            # If the room has some kind of name, use it, but we don't
+            # want the generated-from-names one here otherwise we'll
+            # end up with, "new message from Bob in the Bob room"
+            room_name = calculate_room_name(
+                state_by_room[room_id], user_id, fallback_to_members=False
+            )
+
+            my_member_event = state_by_room[room_id][("m.room.member", user_id)]
+            if my_member_event.content["membership"] == "invite":
+                inviter_member_event = state_by_room[room_id][
+                    ("m.room.member", my_member_event.sender)
+                ]
+                inviter_name = name_from_member_event(inviter_member_event)
+
+                if room_name is None:
+                    return INVITE_FROM_PERSON % {
+                        "person": inviter_name,
+                        "app": self.app_name
+                    }
+                else:
+                    return INVITE_FROM_PERSON_TO_ROOM % {
+                        "person": inviter_name,
+                        "room": room_name,
+                        "app": self.app_name,
+                    }
+
+            sender_name = None
+            if len(notifs_by_room[room_id]) == 1:
+                # There is just the one notification, so give some detail
+                event = notif_events[notifs_by_room[room_id][0]["event_id"]]
+                if ("m.room.member", event.sender) in state_by_room[room_id]:
+                    state_event = state_by_room[room_id][("m.room.member", event.sender)]
+                    sender_name = name_from_member_event(state_event)
+
+                if sender_name is not None and room_name is not None:
+                    return MESSAGE_FROM_PERSON_IN_ROOM % {
+                        "person": sender_name,
+                        "room": room_name,
+                        "app": self.app_name,
+                    }
+                elif sender_name is not None:
+                    return MESSAGE_FROM_PERSON % {
+                        "person": sender_name,
+                        "app": self.app_name,
+                    }
+            else:
+                # There's more than one notification for this room, so just
+                # say there are several
+                if room_name is not None:
+                    return MESSAGES_IN_ROOM % {
+                        "room": room_name,
+                        "app": self.app_name,
+                    }
+                else:
+                    # If the room doesn't have a name, say who the messages
+                    # are from explicitly to avoid, "messages in the Bob room"
+                    sender_ids = list(set([
+                        notif_events[n['event_id']].sender
+                        for n in notifs_by_room[room_id]
+                    ]))
+
+                    return MESSAGES_FROM_PERSON % {
+                        "person": descriptor_from_member_events([
+                            state_by_room[room_id][("m.room.member", s)]
+                            for s in sender_ids
+                        ]),
+                        "app": self.app_name,
+                    }
+        else:
+            # Stuff's happened in multiple different rooms
+            return MESSAGES_IN_ROOMS % {
+                "app": self.app_name,
+            }
+
+    def make_room_link(self, room_id):
+        # need /beta for Universal Links to work on iOS
+        if self.app_name == "Vector":
+            return "https://vector.im/beta/#/room/%s" % (room_id,)
+        else:
+            return "https://matrix.to/#/room/%s" % (room_id,)
+
+    def make_notif_link(self, notif):
+        # need /beta for Universal Links to work on iOS
+        if self.app_name == "Vector":
+            return "https://vector.im/beta/#/room/%s/%s" % (
+                notif['room_id'], notif['event_id']
+            )
+        else:
+            return "https://matrix.to/#/room/%s/%s" % (
+                notif['room_id'], notif['event_id']
+            )
+
+    def make_unsubscribe_link(self):
+        # XXX: matrix.to
+        return "https://vector.im/#/settings"
+
+    def mxc_to_http_filter(self, value, width, height, resize_method="crop"):
+        if value[0:6] != "mxc://":
+            return ""
+
+        serverAndMediaId = value[6:]
+        if '#' in serverAndMediaId:
+            (serverAndMediaId, fragment) = serverAndMediaId.split('#', 1)
+            fragment = "#" + fragment
+
+        params = {
+            "width": width,
+            "height": height,
+            "method": resize_method,
+        }
+        return "%s_matrix/media/v1/thumbnail/%s?%s%s" % (
+            self.hs.config.public_baseurl,
+            serverAndMediaId,
+            urllib.urlencode(params),
+            fragment or "",
+        )
+
+
+def safe_markup(raw_html):
+    return jinja2.Markup(bleach.linkify(bleach.clean(
+        raw_html, tags=ALLOWED_TAGS, attributes=ALLOWED_ATTRS,
+        # bleach master has this, but it isn't released yet
+        # protocols=ALLOWED_SCHEMES,
+        strip=True
+    )))
+
+
+def safe_text(raw_text):
+    """
+    Process text: treat it as HTML but escape any tags (ie. just escape the
+    HTML) then linkify it.
+    """
+    return jinja2.Markup(bleach.linkify(bleach.clean(
+        raw_text, tags=[], attributes={},
+        strip=False
+    )))
+
+
+def deduped_ordered_list(l):
+    seen = set()
+    ret = []
+    for item in l:
+        if item not in seen:
+            seen.add(item)
+            ret.append(item)
+    return ret
+
+
+def string_ordinal_total(s):
+    tot = 0
+    for c in s:
+        tot += ord(c)
+    return tot
+
+
+def format_ts_filter(value, format):
+    return time.strftime(format, time.localtime(value / 1000))
diff --git a/synapse/push/pusher.py b/synapse/push/pusher.py
index 4960837504..e6c0806415 100644
--- a/synapse/push/pusher.py
+++ b/synapse/push/pusher.py
@@ -1,10 +1,37 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 from httppusher import HttpPusher
 
-PUSHER_TYPES = {
-    'http': HttpPusher
-}
+import logging
+logger = logging.getLogger(__name__)
 
 
 def create_pusher(hs, pusherdict):
+    logger.info("trying to create_pusher for %r", pusherdict)
+
+    PUSHER_TYPES = {
+        "http": HttpPusher,
+    }
+
+    logger.info("email enable notifs: %r", hs.config.email_enable_notifs)
+    if hs.config.email_enable_notifs:
+        from synapse.push.emailpusher import EmailPusher
+        PUSHER_TYPES["email"] = EmailPusher
+        logger.info("defined email pusher type")
+
     if pusherdict['kind'] in PUSHER_TYPES:
+        logger.info("found pusher")
         return PUSHER_TYPES[pusherdict['kind']](hs, pusherdict)
diff --git a/synapse/push/pusherpool.py b/synapse/push/pusherpool.py
index 6ef48d63f7..5853ec36a9 100644
--- a/synapse/push/pusherpool.py
+++ b/synapse/push/pusherpool.py
@@ -17,7 +17,6 @@
 from twisted.internet import defer
 
 import pusher
-from synapse.push import PusherConfigException
 from synapse.util.logcontext import preserve_fn
 from synapse.util.async import run_on_reactor
 
@@ -50,6 +49,7 @@ class PusherPool:
         # recreated, added and started: this means we have only one
         # code path adding pushers.
         pusher.create_pusher(self.hs, {
+            "id": None,
             "user_name": user_id,
             "kind": kind,
             "app_id": app_id,
@@ -185,8 +185,8 @@ class PusherPool:
         for pusherdict in pushers:
             try:
                 p = pusher.create_pusher(self.hs, pusherdict)
-            except PusherConfigException:
-                logger.exception("Couldn't start a pusher: caught PusherConfigException")
+            except:
+                logger.exception("Couldn't start a pusher: caught Exception")
                 continue
             if p:
                 appid_pushkey = "%s:%s" % (
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 0eb3d6c1de..e0a7a19777 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -44,6 +44,10 @@ CONDITIONAL_REQUIREMENTS = {
     "preview_url": {
         "netaddr>=0.7.18": ["netaddr"],
     },
+    "email.enable_notifs": {
+        "Jinja2>=2.8": ["Jinja2>=2.8"],
+        "bleach>=1.4.2": ["bleach>=1.4.2"],
+    },
 }
 
 
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index ff8f69ddbf..1ecc02d94d 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -48,6 +48,7 @@ class RegisterRestServlet(RestServlet):
         super(RegisterRestServlet, self).__init__()
         self.hs = hs
         self.auth = hs.get_auth()
+        self.store = hs.get_datastore()
         self.auth_handler = hs.get_handlers().auth_handler
         self.registration_handler = hs.get_handlers().registration_handler
         self.identity_handler = hs.get_handlers().identity_handler
@@ -214,6 +215,34 @@ class RegisterRestServlet(RestServlet):
                         threepid['validated_at'],
                     )
 
+                    # And we add an email pusher for them by default, but only
+                    # if email notifications are enabled (so people don't start
+                    # getting mail spam where they weren't before if email
+                    # notifs are set up on a home server)
+                    if (
+                        self.hs.config.email_enable_notifs and
+                        self.hs.config.email_notif_for_new_users
+                    ):
+                        # Pull the ID of the access token back out of the db
+                        # It would really make more sense for this to be passed
+                        # up when the access token is saved, but that's quite an
+                        # invasive change I'd rather do separately.
+                        user_tuple = yield self.store.get_user_by_access_token(
+                            token
+                        )
+
+                        yield self.hs.get_pusherpool().add_pusher(
+                            user_id=user_id,
+                            access_token=user_tuple["token_id"],
+                            kind="email",
+                            app_id="m.email",
+                            app_display_name="Email Notifications",
+                            device_display_name=threepid["address"],
+                            pushkey=threepid["address"],
+                            lang=None,  # We don't know a user's language here
+                            data={},
+                        )
+
             if 'bind_email' in params and params['bind_email']:
                 logger.info("bind_email specified: binding")
 
diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/event_push_actions.py
index 86a98b6f11..6f316f7d24 100644
--- a/synapse/storage/event_push_actions.py
+++ b/synapse/storage/event_push_actions.py
@@ -118,16 +118,19 @@ class EventPushActionsStore(SQLBaseStore):
                                                   max_stream_ordering=None):
         def get_after_receipt(txn):
             sql = (
-                "SELECT ep.event_id, ep.stream_ordering, ep.actions "
-                "FROM event_push_actions AS ep, ("
-                "   SELECT room_id, user_id,"
-                "       max(topological_ordering) as topological_ordering,"
-                "       max(stream_ordering) as stream_ordering"
+                "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions, "
+                "e.received_ts "
+                "FROM ("
+                "   SELECT room_id, user_id, "
+                "       max(topological_ordering) as topological_ordering, "
+                "       max(stream_ordering) as stream_ordering "
                 "       FROM events"
                 "   NATURAL JOIN receipts_linearized WHERE receipt_type = 'm.read'"
                 "   GROUP BY room_id, user_id"
-                ") AS rl "
-                "WHERE"
+                ") AS rl,"
+                " event_push_actions AS ep"
+                " INNER JOIN events AS e USING (room_id, event_id)"
+                " WHERE"
                 "   ep.room_id = rl.room_id"
                 "   AND ("
                 "       ep.topological_ordering > rl.topological_ordering"
@@ -153,11 +156,13 @@ class EventPushActionsStore(SQLBaseStore):
 
         def get_no_receipt(txn):
             sql = (
-                "SELECT ep.event_id, ep.stream_ordering, ep.actions "
-                "FROM event_push_actions AS ep "
-                "WHERE ep.room_id not in ("
+                "SELECT ep.event_id, ep.room_id, ep.stream_ordering, ep.actions,"
+                " e.received_ts"
+                " FROM event_push_actions AS ep"
+                " JOIN events e ON ep.room_id = e.room_id AND ep.event_id = e.event_id"
+                " WHERE ep.room_id not in ("
                 "   SELECT room_id FROM events NATURAL JOIN receipts_linearized"
-                "   WHERE receipt_type = 'm.read' AND user_id = ? "
+                "   WHERE receipt_type = 'm.read' AND user_id = ?"
                 "   GROUP BY room_id"
                 ") AND ep.user_id = ? AND ep.stream_ordering > ?"
             )
@@ -175,12 +180,30 @@ class EventPushActionsStore(SQLBaseStore):
         defer.returnValue([
             {
                 "event_id": row[0],
-                "stream_ordering": row[1],
-                "actions": json.loads(row[2]),
+                "room_id": row[1],
+                "stream_ordering": row[2],
+                "actions": json.loads(row[3]),
+                "received_ts": row[4],
             } for row in after_read_receipt + no_read_receipt
         ])
 
     @defer.inlineCallbacks
+    def get_time_of_last_push_action_before(self, stream_ordering):
+        def f(txn):
+            sql = (
+                "SELECT e.received_ts"
+                " FROM event_push_actions AS ep"
+                " JOIN events e ON ep.room_id = e.room_id AND ep.event_id = e.event_id"
+                " WHERE ep.stream_ordering > ?"
+                " ORDER BY ep.stream_ordering ASC"
+                " LIMIT 1"
+            )
+            txn.execute(sql, (stream_ordering,))
+            return txn.fetchone()
+        result = yield self.runInteraction("get_time_of_last_push_action_before", f)
+        defer.returnValue(result[0] if result else None)
+
+    @defer.inlineCallbacks
     def get_latest_push_action_stream_ordering(self):
         def f(txn):
             txn.execute("SELECT MAX(stream_ordering) FROM event_push_actions")
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index a27b7919cd..4655669ba0 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -144,6 +144,7 @@ class EventsStore(SQLBaseStore):
 
     def __init__(self, hs):
         super(EventsStore, self).__init__(hs)
+        self._clock = hs.get_clock()
         self.register_background_update_handler(
             self.EVENT_ORIGIN_SERVER_TS_NAME, self._background_reindex_origin_server_ts
         )
@@ -565,6 +566,7 @@ class EventsStore(SQLBaseStore):
                     "outlier": event.internal_metadata.is_outlier(),
                     "content": encode_json(event.content).decode("UTF-8"),
                     "origin_server_ts": int(event.origin_server_ts),
+                    "received_ts": self._clock.time_msec(),
                 }
                 for event, _ in events_and_contexts
             ],
diff --git a/synapse/storage/pusher.py b/synapse/storage/pusher.py
index 11feb3eb11..d9afd7ec87 100644
--- a/synapse/storage/pusher.py
+++ b/synapse/storage/pusher.py
@@ -233,3 +233,30 @@ class PusherStore(SQLBaseStore):
             {'failing_since': failing_since},
             desc="update_pusher_failing_since",
         )
+
+    @defer.inlineCallbacks
+    def get_throttle_params_by_room(self, pusher_id):
+        res = yield self._simple_select_list(
+            "pusher_throttle",
+            {"pusher": pusher_id},
+            ["room_id", "last_sent_ts", "throttle_ms"],
+            desc="get_throttle_params_by_room"
+        )
+
+        params_by_room = {}
+        for row in res:
+            params_by_room[row["room_id"]] = {
+                "last_sent_ts": row["last_sent_ts"],
+                "throttle_ms": row["throttle_ms"]
+            }
+
+        defer.returnValue(params_by_room)
+
+    @defer.inlineCallbacks
+    def set_throttle_params(self, pusher_id, room_id, params):
+        yield self._simple_upsert(
+            "pusher_throttle",
+            {"pusher": pusher_id, "room_id": room_id},
+            params,
+            desc="set_throttle_params"
+        )
diff --git a/synapse/storage/schema/delta/31/events.sql b/synapse/storage/schema/delta/31/events.sql
new file mode 100644
index 0000000000..1dd0f9e170
--- /dev/null
+++ b/synapse/storage/schema/delta/31/events.sql
@@ -0,0 +1,16 @@
+/* Copyright 2016 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+ALTER TABLE events ADD COLUMN received_ts BIGINT;
diff --git a/synapse/storage/schema/delta/31/pusher_throttle.sql b/synapse/storage/schema/delta/31/pusher_throttle.sql
new file mode 100644
index 0000000000..d86d30c13c
--- /dev/null
+++ b/synapse/storage/schema/delta/31/pusher_throttle.sql
@@ -0,0 +1,23 @@
+/* Copyright 2016 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+CREATE TABLE pusher_throttle(
+    pusher BIGINT NOT NULL,
+    room_id TEXT NOT NULL,
+    last_sent_ts BIGINT,
+    throttle_ms BIGINT,
+    PRIMARY KEY (pusher, room_id)
+);
diff --git a/synapse/util/presentable_names.py b/synapse/util/presentable_names.py
new file mode 100644
index 0000000000..3efa8a8206
--- /dev/null
+++ b/synapse/util/presentable_names.py
@@ -0,0 +1,159 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import re
+
+# intentionally looser than what aliases we allow to be registered since
+# other HSes may allow aliases that we would not
+ALIAS_RE = re.compile(r"^#.*:.+$")
+
+ALL_ALONE = "Empty Room"
+
+
+def calculate_room_name(room_state, user_id, fallback_to_members=True):
+    """
+    Works out a user-facing name for the given room as per Matrix
+    spec recommendations.
+    Does not yet support internationalisation.
+    Args:
+        room_state: Dictionary of the room's state
+        user_id: The ID of the user to whom the room name is being presented
+        fallback_to_members: If False, return None instead of generating a name
+                             based on the room's members if the room has no
+                             title or aliases.
+
+    Returns:
+        (string or None) A human readable name for the room.
+    """
+    # does it have a name?
+    if ("m.room.name", "") in room_state:
+        m_room_name = room_state[("m.room.name", "")]
+        if m_room_name.content and m_room_name.content["name"]:
+            return m_room_name.content["name"]
+
+    # does it have a canonical alias?
+    if ("m.room.canonical_alias", "") in room_state:
+        canon_alias = room_state[("m.room.canonical_alias", "")]
+        if (
+            canon_alias.content and canon_alias.content["alias"] and
+            _looks_like_an_alias(canon_alias.content["alias"])
+        ):
+            return canon_alias.content["alias"]
+
+    # at this point we're going to need to search the state by all state keys
+    # for an event type, so rearrange the data structure
+    room_state_bytype = _state_as_two_level_dict(room_state)
+
+    # right then, any aliases at all?
+    if "m.room.aliases" in room_state_bytype:
+        m_room_aliases = room_state_bytype["m.room.aliases"]
+        if len(m_room_aliases.values()) > 0:
+            first_alias_event = m_room_aliases.values()[0]
+            if first_alias_event.content and first_alias_event.content["aliases"]:
+                the_aliases = first_alias_event.content["aliases"]
+                if len(the_aliases) > 0 and _looks_like_an_alias(the_aliases[0]):
+                    return the_aliases[0]
+
+    if not fallback_to_members:
+        return None
+
+    my_member_event = None
+    if ("m.room.member", user_id) in room_state:
+        my_member_event = room_state[("m.room.member", user_id)]
+
+    if (
+        my_member_event is not None and
+        my_member_event.content['membership'] == "invite"
+    ):
+        if ("m.room.member", my_member_event.sender) in room_state:
+            inviter_member_event = room_state[("m.room.member", my_member_event.sender)]
+            return "Invite from %s" % (name_from_member_event(inviter_member_event),)
+        else:
+            return "Room Invite"
+
+    # we're going to have to generate a name based on who's in the room,
+    # so find out who is in the room that isn't the user.
+    if "m.room.member" in room_state_bytype:
+        all_members = [
+            ev for ev in room_state_bytype["m.room.member"].values()
+            if ev.content['membership'] == "join" or ev.content['membership'] == "invite"
+        ]
+        # Sort the member events oldest-first so the we name people in the
+        # order the joined (it should at least be deterministic rather than
+        # dictionary iteration order)
+        all_members.sort(key=lambda e: e.origin_server_ts)
+        other_members = [m for m in all_members if m.state_key != user_id]
+    else:
+        other_members = []
+        all_members = []
+
+    if len(other_members) == 0:
+        if len(all_members) == 1:
+            # self-chat, peeked room with 1 participant,
+            # or inbound invite, or outbound 3PID invite.
+            if all_members[0].sender == user_id:
+                if "m.room.third_party_invite" in room_state_bytype:
+                    third_party_invites = room_state_bytype["m.room.third_party_invite"]
+                    if len(third_party_invites) > 0:
+                        # technically third party invite events are not member
+                        # events, but they are close enough
+                        return "Inviting %s" (
+                            descriptor_from_member_events(third_party_invites)
+                        )
+                    else:
+                        return ALL_ALONE
+            else:
+                return name_from_member_event(all_members[0])
+        else:
+            return ALL_ALONE
+    else:
+        return descriptor_from_member_events(other_members)
+
+
+def descriptor_from_member_events(member_events):
+    if len(member_events) == 0:
+        return "nobody"
+    elif len(member_events) == 1:
+        return name_from_member_event(member_events[0])
+    elif len(member_events) == 2:
+        return "%s and %s" % (
+            name_from_member_event(member_events[0]),
+            name_from_member_event(member_events[1]),
+        )
+    else:
+        return "%s and %d others" % (
+            name_from_member_event(member_events[0]),
+            len(member_events) - 1,
+        )
+
+
+def name_from_member_event(member_event):
+    if (
+        member_event.content and "displayname" in member_event.content and
+        member_event.content["displayname"]
+    ):
+        return member_event.content["displayname"]
+    return member_event.state_key
+
+
+def _state_as_two_level_dict(state):
+    ret = {}
+    for k, v in state.items():
+        ret.setdefault(k[0], {})[k[1]] = v
+    return ret
+
+
+def _looks_like_an_alias(string):
+    return ALIAS_RE.match(string) is not None