Merge tag 'v1.66.0rc1' into develop

Synapse 1.66.0rc1 (2022-08-23)
==============================

This release removes the ability for homeservers to delegate email ownership
verification and password reset confirmation to identity servers. This removal
was originally planned for Synapse 1.64, but was later deferred until now.

See the [upgrade notes](https://matrix-org.github.io/synapse/v1.66/upgrade.html#upgrading-to-v1660) for more details.

Features
--------

- Improve validation of request bodies for the following client-server API endpoints: [`/account/password`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpassword), [`/account/password/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpasswordemailrequesttoken), [`/account/deactivate`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountdeactivate) and [`/account/3pid/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3account3pidemailrequesttoken). ([\#13188](https://github.com/matrix-org/synapse/issues/13188), [\#13563](https://github.com/matrix-org/synapse/issues/13563))
- Add forgotten status to [Room Details Admin API](https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#room-details-api). ([\#13503](https://github.com/matrix-org/synapse/issues/13503))
- Add an experimental implementation for [MSC3852 (Expose user agents on `Device`)](https://github.com/matrix-org/matrix-spec-proposals/pull/3852). ([\#13549](https://github.com/matrix-org/synapse/issues/13549))
- Add `org.matrix.msc2716v4` experimental room version with updated content fields. Part of [MSC2716 (Importing history)](https://github.com/matrix-org/matrix-spec-proposals/pull/2716).  ([\#13551](https://github.com/matrix-org/synapse/issues/13551))
- Add support for compression to federation responses. ([\#13537](https://github.com/matrix-org/synapse/issues/13537))
- Improve performance of sending messages in rooms with thousands of local users. ([\#13522](https://github.com/matrix-org/synapse/issues/13522), [\#13547](https://github.com/matrix-org/synapse/issues/13547))

Bugfixes
--------

- Faster room joins: make `/joined_members` block whilst the room is partial stated. ([\#13514](https://github.com/matrix-org/synapse/issues/13514))
- Fix a bug introduced in Synapse 1.21.0 where the [`/event_reports` Admin API](https://matrix-org.github.io/synapse/develop/admin_api/event_reports.html) could return a total count which was larger than the number of results you can actually query for. ([\#13525](https://github.com/matrix-org/synapse/issues/13525))
- Fix a bug introduced in Synapse 1.52.0 where sending server notices fails if `max_avatar_size` or `allowed_avatar_mimetypes` is set and not `system_mxid_avatar_url`. ([\#13566](https://github.com/matrix-org/synapse/issues/13566))
- Fix a bug where the `opentracing.force_tracing_for_users` config option would not apply to [`/sendToDevice`](https://spec.matrix.org/v1.3/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid) and [`/keys/upload`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3keysupload) requests. ([\#13574](https://github.com/matrix-org/synapse/issues/13574))

Improved Documentation
----------------------

- Add `openssl` example for generating registration HMAC digest. ([\#13472](https://github.com/matrix-org/synapse/issues/13472))
- Tidy up Synapse's README. ([\#13491](https://github.com/matrix-org/synapse/issues/13491))
- Document that event purging related to the `redaction_retention_period` config option is executed only every 5 minutes. ([\#13492](https://github.com/matrix-org/synapse/issues/13492))
- Add a warning to retention documentation regarding the possibility of database corruption. ([\#13497](https://github.com/matrix-org/synapse/issues/13497))
- Document that the `DOCKER_BUILDKIT=1` flag is needed to build the docker image. ([\#13515](https://github.com/matrix-org/synapse/issues/13515))
- Add missing links in `user_consent` section of configuration manual. ([\#13536](https://github.com/matrix-org/synapse/issues/13536))
- Fix the doc and some warnings that were referring to the nonexistent `custom_templates_directory` setting (instead of `custom_template_directory`). ([\#13538](https://github.com/matrix-org/synapse/issues/13538))

Deprecations and Removals
-------------------------

- Remove the ability for homeservers to delegate email ownership verification
  and password reset confirmation to identity servers. See [upgrade notes](https://matrix-org.github.io/synapse/v1.66/upgrade.html#upgrading-to-v1660) for more details.

Internal Changes
----------------

- Update the rejected state of events during de-partial-stating. ([\#13459](https://github.com/matrix-org/synapse/issues/13459))
- Avoid blocking lazy-loading `/sync`s during partial joins due to remote memberships. Pull remote memberships from auth events instead of the room state. ([\#13477](https://github.com/matrix-org/synapse/issues/13477))
- Refuse to start when faster joins is enabled on a deployment with workers, since worker configurations are not currently supported. ([\#13531](https://github.com/matrix-org/synapse/issues/13531))

- Allow use of both `@trace` and `@tag_args` stacked on the same function. ([\#13453](https://github.com/matrix-org/synapse/issues/13453))
- Instrument the federation/backfill part of `/messages` for understandable traces in Jaeger. ([\#13489](https://github.com/matrix-org/synapse/issues/13489))
- Instrument `FederationStateIdsServlet` (`/state_ids`) for understandable traces in Jaeger. ([\#13499](https://github.com/matrix-org/synapse/issues/13499), [\#13554](https://github.com/matrix-org/synapse/issues/13554))
- Track HTTP response times over 10 seconds from `/messages` (`synapse_room_message_list_rest_servlet_response_time_seconds`). ([\#13533](https://github.com/matrix-org/synapse/issues/13533))
- Add metrics to track how the rate limiter is affecting requests (sleep/reject). ([\#13534](https://github.com/matrix-org/synapse/issues/13534), [\#13541](https://github.com/matrix-org/synapse/issues/13541))
- Add metrics to time how long it takes us to do backfill processing (`synapse_federation_backfill_processing_before_time_seconds`, `synapse_federation_backfill_processing_after_time_seconds`). ([\#13535](https://github.com/matrix-org/synapse/issues/13535), [\#13584](https://github.com/matrix-org/synapse/issues/13584))
- Add metrics to track rate limiter queue timing (`synapse_rate_limit_queue_wait_time_seconds`). ([\#13544](https://github.com/matrix-org/synapse/issues/13544))
- Update metrics to track `/messages` response time by room size. ([\#13545](https://github.com/matrix-org/synapse/issues/13545))

- Refactor methods in `synapse.api.auth.Auth` to use `Requester` objects everywhere instead of user IDs. ([\#13024](https://github.com/matrix-org/synapse/issues/13024))
- Clean-up tests for notifications. ([\#13471](https://github.com/matrix-org/synapse/issues/13471))
- Add some miscellaneous comments to document sync, especially around `compute_state_delta`. ([\#13474](https://github.com/matrix-org/synapse/issues/13474))
- Use literals in place of `HTTPStatus` constants in tests. ([\#13479](https://github.com/matrix-org/synapse/issues/13479), [\#13488](https://github.com/matrix-org/synapse/issues/13488))
- Add comments about how event push actions are rotated. ([\#13485](https://github.com/matrix-org/synapse/issues/13485))
- Modify HTML template content to better support mobile devices' screen sizes. ([\#13493](https://github.com/matrix-org/synapse/issues/13493))
- Add a linter script which will reject non-strict types in Pydantic models. ([\#13502](https://github.com/matrix-org/synapse/issues/13502))
- Reduce the number of tests using legacy TCP replication. ([\#13543](https://github.com/matrix-org/synapse/issues/13543))
- Allow specifying additional request fields when using the `HomeServerTestCase.login` helper method. ([\#13549](https://github.com/matrix-org/synapse/issues/13549))
- Make `HomeServerTestCase` load any configured homeserver modules automatically. ([\#13558](https://github.com/matrix-org/synapse/issues/13558))

59 files changed, 185 insertions, 291 deletions

diff --git a/CHANGES.md b/CHANGES.md
index 8a023b769f..14fafc260d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,84 @@
+Synapse 1.66.0rc1 (2022-08-23)
+==============================
+
+This release removes the ability for homeservers to delegate email ownership
+verification and password reset confirmation to identity servers. This removal
+was originally planned for Synapse 1.64, but was later deferred until now.
+
+See the [upgrade notes](https://matrix-org.github.io/synapse/v1.66/upgrade.html#upgrading-to-v1660) for more details.
+
+Features
+--------
+
+- Improve validation of request bodies for the following client-server API endpoints: [`/account/password`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpassword), [`/account/password/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpasswordemailrequesttoken), [`/account/deactivate`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountdeactivate) and [`/account/3pid/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3account3pidemailrequesttoken). ([\#13188](https://github.com/matrix-org/synapse/issues/13188), [\#13563](https://github.com/matrix-org/synapse/issues/13563))
+- Add forgotten status to [Room Details Admin API](https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#room-details-api). ([\#13503](https://github.com/matrix-org/synapse/issues/13503))
+- Add an experimental implementation for [MSC3852 (Expose user agents on `Device`)](https://github.com/matrix-org/matrix-spec-proposals/pull/3852). ([\#13549](https://github.com/matrix-org/synapse/issues/13549))
+- Add `org.matrix.msc2716v4` experimental room version with updated content fields. Part of [MSC2716 (Importing history)](https://github.com/matrix-org/matrix-spec-proposals/pull/2716).  ([\#13551](https://github.com/matrix-org/synapse/issues/13551))
+- Add support for compression to federation responses. ([\#13537](https://github.com/matrix-org/synapse/issues/13537))
+- Improve performance of sending messages in rooms with thousands of local users. ([\#13522](https://github.com/matrix-org/synapse/issues/13522), [\#13547](https://github.com/matrix-org/synapse/issues/13547))
+
+
+Bugfixes
+--------
+
+- Faster room joins: make `/joined_members` block whilst the room is partial stated. ([\#13514](https://github.com/matrix-org/synapse/issues/13514))
+- Fix a bug introduced in Synapse 1.21.0 where the [`/event_reports` Admin API](https://matrix-org.github.io/synapse/develop/admin_api/event_reports.html) could return a total count which was larger than the number of results you can actually query for. ([\#13525](https://github.com/matrix-org/synapse/issues/13525))
+- Fix a bug introduced in Synapse 1.52.0 where sending server notices fails if `max_avatar_size` or `allowed_avatar_mimetypes` is set and not `system_mxid_avatar_url`. ([\#13566](https://github.com/matrix-org/synapse/issues/13566))
+- Fix a bug where the `opentracing.force_tracing_for_users` config option would not apply to [`/sendToDevice`](https://spec.matrix.org/v1.3/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid) and [`/keys/upload`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3keysupload) requests. ([\#13574](https://github.com/matrix-org/synapse/issues/13574))
+
+
+Improved Documentation
+----------------------
+
+- Add `openssl` example for generating registration HMAC digest. ([\#13472](https://github.com/matrix-org/synapse/issues/13472))
+- Tidy up Synapse's README. ([\#13491](https://github.com/matrix-org/synapse/issues/13491))
+- Document that event purging related to the `redaction_retention_period` config option is executed only every 5 minutes. ([\#13492](https://github.com/matrix-org/synapse/issues/13492))
+- Add a warning to retention documentation regarding the possibility of database corruption. ([\#13497](https://github.com/matrix-org/synapse/issues/13497))
+- Document that the `DOCKER_BUILDKIT=1` flag is needed to build the docker image. ([\#13515](https://github.com/matrix-org/synapse/issues/13515))
+- Add missing links in `user_consent` section of configuration manual. ([\#13536](https://github.com/matrix-org/synapse/issues/13536))
+- Fix the doc and some warnings that were referring to the nonexistent `custom_templates_directory` setting (instead of `custom_template_directory`). ([\#13538](https://github.com/matrix-org/synapse/issues/13538))
+
+
+Deprecations and Removals
+-------------------------
+
+- Remove the ability for homeservers to delegate email ownership verification
+  and password reset confirmation to identity servers. See [upgrade notes](https://matrix-org.github.io/synapse/v1.66/upgrade.html#upgrading-to-v1660) for more details.
+
+Internal Changes
+----------------
+
+### Faster room joins
+
+- Update the rejected state of events during de-partial-stating. ([\#13459](https://github.com/matrix-org/synapse/issues/13459))
+- Avoid blocking lazy-loading `/sync`s during partial joins due to remote memberships. Pull remote memberships from auth events instead of the room state. ([\#13477](https://github.com/matrix-org/synapse/issues/13477))
+- Refuse to start when faster joins is enabled on a deployment with workers, since worker configurations are not currently supported. ([\#13531](https://github.com/matrix-org/synapse/issues/13531))
+
+### Metrics and tracing
+
+- Allow use of both `@trace` and `@tag_args` stacked on the same function. ([\#13453](https://github.com/matrix-org/synapse/issues/13453))
+- Instrument the federation/backfill part of `/messages` for understandable traces in Jaeger. ([\#13489](https://github.com/matrix-org/synapse/issues/13489))
+- Instrument `FederationStateIdsServlet` (`/state_ids`) for understandable traces in Jaeger. ([\#13499](https://github.com/matrix-org/synapse/issues/13499), [\#13554](https://github.com/matrix-org/synapse/issues/13554))
+- Track HTTP response times over 10 seconds from `/messages` (`synapse_room_message_list_rest_servlet_response_time_seconds`). ([\#13533](https://github.com/matrix-org/synapse/issues/13533))
+- Add metrics to track how the rate limiter is affecting requests (sleep/reject). ([\#13534](https://github.com/matrix-org/synapse/issues/13534), [\#13541](https://github.com/matrix-org/synapse/issues/13541))
+- Add metrics to time how long it takes us to do backfill processing (`synapse_federation_backfill_processing_before_time_seconds`, `synapse_federation_backfill_processing_after_time_seconds`). ([\#13535](https://github.com/matrix-org/synapse/issues/13535), [\#13584](https://github.com/matrix-org/synapse/issues/13584))
+- Add metrics to track rate limiter queue timing (`synapse_rate_limit_queue_wait_time_seconds`). ([\#13544](https://github.com/matrix-org/synapse/issues/13544))
+- Update metrics to track `/messages` response time by room size. ([\#13545](https://github.com/matrix-org/synapse/issues/13545))
+
+### Everything else
+
+- Refactor methods in `synapse.api.auth.Auth` to use `Requester` objects everywhere instead of user IDs. ([\#13024](https://github.com/matrix-org/synapse/issues/13024))
+- Clean-up tests for notifications. ([\#13471](https://github.com/matrix-org/synapse/issues/13471))
+- Add some miscellaneous comments to document sync, especially around `compute_state_delta`. ([\#13474](https://github.com/matrix-org/synapse/issues/13474))
+- Use literals in place of `HTTPStatus` constants in tests. ([\#13479](https://github.com/matrix-org/synapse/issues/13479), [\#13488](https://github.com/matrix-org/synapse/issues/13488))
+- Add comments about how event push actions are rotated. ([\#13485](https://github.com/matrix-org/synapse/issues/13485))
+- Modify HTML template content to better support mobile devices' screen sizes. ([\#13493](https://github.com/matrix-org/synapse/issues/13493))
+- Add a linter script which will reject non-strict types in Pydantic models. ([\#13502](https://github.com/matrix-org/synapse/issues/13502))
+- Reduce the number of tests using legacy TCP replication. ([\#13543](https://github.com/matrix-org/synapse/issues/13543))
+- Allow specifying additional request fields when using the `HomeServerTestCase.login` helper method. ([\#13549](https://github.com/matrix-org/synapse/issues/13549))
+- Make `HomeServerTestCase` load any configured homeserver modules automatically. ([\#13558](https://github.com/matrix-org/synapse/issues/13558))
+
+
 Synapse 1.65.0 (2022-08-16)
 ===========================
 
diff --git a/changelog.d/13024.misc b/changelog.d/13024.misc
deleted file mode 100644
index aa43c82429..0000000000
--- a/changelog.d/13024.misc
+++ /dev/null
@@ -1 +0,0 @@
-Refactor methods in `synapse.api.auth.Auth` to use `Requester` objects everywhere instead of user IDs.
diff --git a/changelog.d/13188.feature b/changelog.d/13188.feature
deleted file mode 100644
index 4c39b74289..0000000000
--- a/changelog.d/13188.feature
+++ /dev/null
@@ -1 +0,0 @@
-Improve validation of request bodies for the following client-server API endpoints: [`/account/password`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpassword), [`/account/password/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpasswordemailrequesttoken), [`/account/deactivate`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountdeactivate) and [`/account/3pid/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3account3pidemailrequesttoken).
diff --git a/changelog.d/13453.misc b/changelog.d/13453.misc
deleted file mode 100644
index d30c5230c8..0000000000
--- a/changelog.d/13453.misc
+++ /dev/null
@@ -1 +0,0 @@
-Allow use of both `@trace` and `@tag_args` stacked on the same function (tracing).
diff --git a/changelog.d/13459.misc b/changelog.d/13459.misc
deleted file mode 100644
index e6082210a0..0000000000
--- a/changelog.d/13459.misc
+++ /dev/null
@@ -1 +0,0 @@
-Faster joins: update the rejected state of events during de-partial-stating.
diff --git a/changelog.d/13471.misc b/changelog.d/13471.misc
deleted file mode 100644
index b55ff32c76..0000000000
--- a/changelog.d/13471.misc
+++ /dev/null
@@ -1 +0,0 @@
-Clean-up tests for notifications.
diff --git a/changelog.d/13472.doc b/changelog.d/13472.doc
deleted file mode 100644
index 2ff6317300..0000000000
--- a/changelog.d/13472.doc
+++ /dev/null
@@ -1 +0,0 @@
-Add `openssl` example for generating registration HMAC digest.
diff --git a/changelog.d/13474.misc b/changelog.d/13474.misc
deleted file mode 100644
index d34c661fed..0000000000
--- a/changelog.d/13474.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add some miscellaneous comments to document sync, especially around `compute_state_delta`.
diff --git a/changelog.d/13477.misc b/changelog.d/13477.misc
deleted file mode 100644
index 5d21ae9d7a..0000000000
--- a/changelog.d/13477.misc
+++ /dev/null
@@ -1 +0,0 @@
-Faster room joins: Avoid blocking lazy-loading `/sync`s during partial joins due to remote memberships. Pull remote memberships from auth events instead of the room state.
diff --git a/changelog.d/13479.misc b/changelog.d/13479.misc
deleted file mode 100644
index 315930deab..0000000000
--- a/changelog.d/13479.misc
+++ /dev/null
@@ -1 +0,0 @@
-Use literals in place of `HTTPStatus` constants in tests.
\ No newline at end of file
diff --git a/changelog.d/13485.misc b/changelog.d/13485.misc
deleted file mode 100644
index c75712b9ff..0000000000
--- a/changelog.d/13485.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add comments about how event push actions are rotated.
diff --git a/changelog.d/13488.misc b/changelog.d/13488.misc
deleted file mode 100644
index 315930deab..0000000000
--- a/changelog.d/13488.misc
+++ /dev/null
@@ -1 +0,0 @@
-Use literals in place of `HTTPStatus` constants in tests.
\ No newline at end of file
diff --git a/changelog.d/13489.misc b/changelog.d/13489.misc
deleted file mode 100644
index 5e4853860e..0000000000
--- a/changelog.d/13489.misc
+++ /dev/null
@@ -1 +0,0 @@
-Instrument the federation/backfill part of `/messages` for understandable traces in Jaeger.
diff --git a/changelog.d/13491.doc b/changelog.d/13491.doc
deleted file mode 100644
index 026f735549..0000000000
--- a/changelog.d/13491.doc
+++ /dev/null
@@ -1 +0,0 @@
-Tidy up Synapse's README.
diff --git a/changelog.d/13492.doc b/changelog.d/13492.doc
deleted file mode 100644
index fc4850d556..0000000000
--- a/changelog.d/13492.doc
+++ /dev/null
@@ -1 +0,0 @@
-Document that event purging related to the `redaction_retention_period` config option is executed only every 5 minutes.
diff --git a/changelog.d/13493.misc b/changelog.d/13493.misc
deleted file mode 100644
index d7d5c33a89..0000000000
--- a/changelog.d/13493.misc
+++ /dev/null
@@ -1 +0,0 @@
-Modify HTML template content to better support mobile devices' screen sizes.
\ No newline at end of file
diff --git a/changelog.d/13497.doc b/changelog.d/13497.doc
deleted file mode 100644
index ef6dc2308d..0000000000
--- a/changelog.d/13497.doc
+++ /dev/null
@@ -1,2 +0,0 @@
-Add a warning to retention documentation regarding the possibility of database corruption.
-
diff --git a/changelog.d/13499.misc b/changelog.d/13499.misc
deleted file mode 100644
index 99dbcebec8..0000000000
--- a/changelog.d/13499.misc
+++ /dev/null
@@ -1 +0,0 @@
-Instrument `FederationStateIdsServlet` (`/state_ids`) for understandable traces in Jaeger.
diff --git a/changelog.d/13502.misc b/changelog.d/13502.misc
deleted file mode 100644
index ed6832996e..0000000000
--- a/changelog.d/13502.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add a linter script which will reject non-strict types in Pydantic models.
diff --git a/changelog.d/13503.feature b/changelog.d/13503.feature
deleted file mode 100644
index 4baabd1e32..0000000000
--- a/changelog.d/13503.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add forgotten status to Room Details API.
\ No newline at end of file
diff --git a/changelog.d/13514.bugfix b/changelog.d/13514.bugfix
deleted file mode 100644
index 7498af0e47..0000000000
--- a/changelog.d/13514.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Faster room joins: make `/joined_members` block whilst the room is partial stated.
\ No newline at end of file
diff --git a/changelog.d/13515.doc b/changelog.d/13515.doc
deleted file mode 100644
index a4d9d97dcb..0000000000
--- a/changelog.d/13515.doc
+++ /dev/null
@@ -1 +0,0 @@
-Document that the `DOCKER_BUILDKIT=1` flag is needed to build the docker image.
\ No newline at end of file
diff --git a/changelog.d/13522.misc b/changelog.d/13522.misc
deleted file mode 100644
index 0a8827205d..0000000000
--- a/changelog.d/13522.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve performance of sending messages in rooms with thousands of local users.
diff --git a/changelog.d/13525.bugfix b/changelog.d/13525.bugfix
deleted file mode 100644
index dbd1adbc88..0000000000
--- a/changelog.d/13525.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a bug in the `/event_reports` Admin API which meant that the total count could be larger than the number of results you can actually query for.
\ No newline at end of file
diff --git a/changelog.d/13531.misc b/changelog.d/13531.misc
deleted file mode 100644
index 986122d3d0..0000000000
--- a/changelog.d/13531.misc
+++ /dev/null
@@ -1 +0,0 @@
-Faster room joins: Refuse to start when faster joins is enabled on a deployment with workers, since worker configurations are not currently supported.
diff --git a/changelog.d/13533.misc b/changelog.d/13533.misc
deleted file mode 100644
index ab4b18887a..0000000000
--- a/changelog.d/13533.misc
+++ /dev/null
@@ -1 +0,0 @@
-Track HTTP response times over 10 seconds from `/messages` (`synapse_room_message_list_rest_servlet_response_time_seconds`).
diff --git a/changelog.d/13534.misc b/changelog.d/13534.misc
deleted file mode 100644
index b488bf74c3..0000000000
--- a/changelog.d/13534.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add metrics to track how the rate limiter is affecting requests (sleep/reject).
diff --git a/changelog.d/13535.misc b/changelog.d/13535.misc
deleted file mode 100644
index 6b190181c8..0000000000
--- a/changelog.d/13535.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add metrics to time how long it takes us to do backfill processing (`synapse_federation_backfill_processing_before_time_seconds`, `synapse_federation_backfill_processing_after_time_seconds`).
diff --git a/changelog.d/13536.doc b/changelog.d/13536.doc
deleted file mode 100644
index c8752acb77..0000000000
--- a/changelog.d/13536.doc
+++ /dev/null
@@ -1 +0,0 @@
-Add missing links in `user_consent` section of configuration manual.
diff --git a/changelog.d/13537.bugfix b/changelog.d/13537.bugfix
deleted file mode 100644
index db843504b1..0000000000
--- a/changelog.d/13537.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Add support for compression to federation responses.
diff --git a/changelog.d/13538.doc b/changelog.d/13538.doc
deleted file mode 100644
index 9215aeac5a..0000000000
--- a/changelog.d/13538.doc
+++ /dev/null
@@ -1 +0,0 @@
-Fix the doc and some warnings that were referring to the nonexistent `custom_templates_directory` setting (instead of `custom_template_directory`).
\ No newline at end of file
diff --git a/changelog.d/13541.misc b/changelog.d/13541.misc
deleted file mode 100644
index b488bf74c3..0000000000
--- a/changelog.d/13541.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add metrics to track how the rate limiter is affecting requests (sleep/reject).
diff --git a/changelog.d/13543.misc b/changelog.d/13543.misc
deleted file mode 100644
index 0300f46cd8..0000000000
--- a/changelog.d/13543.misc
+++ /dev/null
@@ -1 +0,0 @@
-Reduce the number of tests using legacy TCP replication.
diff --git a/changelog.d/13544.misc b/changelog.d/13544.misc
deleted file mode 100644
index d84ba3f076..0000000000
--- a/changelog.d/13544.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add metrics to track rate limiter queue timing (`synapse_rate_limit_queue_wait_time_seconds`).
diff --git a/changelog.d/13545.misc b/changelog.d/13545.misc
deleted file mode 100644
index 1cdbef179e..0000000000
--- a/changelog.d/13545.misc
+++ /dev/null
@@ -1 +0,0 @@
-Update metrics to track `/messages` response time by room size.
diff --git a/changelog.d/13547.misc b/changelog.d/13547.misc
deleted file mode 100644
index 0a8827205d..0000000000
--- a/changelog.d/13547.misc
+++ /dev/null
@@ -1 +0,0 @@
-Improve performance of sending messages in rooms with thousands of local users.
diff --git a/changelog.d/13549.feature b/changelog.d/13549.feature
deleted file mode 100644
index b6a726789c..0000000000
--- a/changelog.d/13549.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add an experimental implementation for [MSC3852](https://github.com/matrix-org/matrix-spec-proposals/pull/3852).
\ No newline at end of file
diff --git a/changelog.d/13549.misc b/changelog.d/13549.misc
deleted file mode 100644
index 5b4303e87e..0000000000
--- a/changelog.d/13549.misc
+++ /dev/null
@@ -1 +0,0 @@
-Allow specifying additional request fields when using the `HomeServerTestCase.login` helper method.
\ No newline at end of file
diff --git a/changelog.d/13551.feature b/changelog.d/13551.feature
deleted file mode 100644
index 365673a3c1..0000000000
--- a/changelog.d/13551.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add `org.matrix.msc2716v4` experimental room version with updated content fields.
diff --git a/changelog.d/13554.misc b/changelog.d/13554.misc
deleted file mode 100644
index 99dbcebec8..0000000000
--- a/changelog.d/13554.misc
+++ /dev/null
@@ -1 +0,0 @@
-Instrument `FederationStateIdsServlet` (`/state_ids`) for understandable traces in Jaeger.
diff --git a/changelog.d/13558.misc b/changelog.d/13558.misc
deleted file mode 100644
index e3f3e31740..0000000000
--- a/changelog.d/13558.misc
+++ /dev/null
@@ -1 +0,0 @@
-Make `HomeServerTestCase` load any configured homeserver modules automatically.
\ No newline at end of file
diff --git a/changelog.d/13563.feature b/changelog.d/13563.feature
deleted file mode 100644
index 4c39b74289..0000000000
--- a/changelog.d/13563.feature
+++ /dev/null
@@ -1 +0,0 @@
-Improve validation of request bodies for the following client-server API endpoints: [`/account/password`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpassword), [`/account/password/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountpasswordemailrequesttoken), [`/account/deactivate`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3accountdeactivate) and [`/account/3pid/email/requestToken`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3account3pidemailrequesttoken).
diff --git a/changelog.d/13566.bugfix b/changelog.d/13566.bugfix
deleted file mode 100644
index 6c44024add..0000000000
--- a/changelog.d/13566.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix a bug introduced in Synapse 1.52.0 where sending server notices fails if `max_avatar_size` or `allowed_avatar_mimetypes` is set and not `system_mxid_avatar_url`.
\ No newline at end of file
diff --git a/changelog.d/13574.bugfix b/changelog.d/13574.bugfix
deleted file mode 100644
index 3899c137aa..0000000000
--- a/changelog.d/13574.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix the `opentracing.force_tracing_for_users` config option not applying to [`/sendToDevice`](https://spec.matrix.org/v1.3/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid) and [`/keys/upload`](https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3keysupload) requests.
\ No newline at end of file
diff --git a/changelog.d/13584.misc b/changelog.d/13584.misc
deleted file mode 100644
index 6b190181c8..0000000000
--- a/changelog.d/13584.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add metrics to time how long it takes us to do backfill processing (`synapse_federation_backfill_processing_before_time_seconds`, `synapse_federation_backfill_processing_after_time_seconds`).
diff --git a/debian/changelog b/debian/changelog
index 917249f940..c3974261a9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.66.0~rc1) stable; urgency=medium
+
+  * New Synapse release 1.66.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 23 Aug 2022 09:48:55 +0100
+
 matrix-synapse-py3 (1.65.0) stable; urgency=medium
 
   * New Synapse release 1.65.0.
diff --git a/docs/admin_api/rooms.md b/docs/admin_api/rooms.md
index ac7c54c20e..7526956bec 100644
--- a/docs/admin_api/rooms.md
+++ b/docs/admin_api/rooms.md
@@ -337,6 +337,8 @@ A response body like the following is returned:
 }
 ```
 
+_Changed in Synapse 1.66:_ Added the `forgotten` key to the response body.
+
 # Room Members API
 
 The Room Members admin API allows server admins to get a list of all members of a room.
diff --git a/docs/upgrade.md b/docs/upgrade.md
index 47a74b67de..0ab5bfeaf0 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -89,6 +89,25 @@ process, for example:
     dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
     ```
 
+# Upgrading to v1.66.0
+
+## Delegation of email validation no longer supported
+
+As of this version, Synapse no longer allows the tasks of verifying email address
+ownership, and password reset confirmation, to be delegated to an identity server.
+This removal was previously planned for Synapse 1.64.0, but was
+[delayed](https://github.com/matrix-org/synapse/issues/13421) until now to give
+homeserver administrators more notice of the change.
+
+To continue to allow users to add email addresses to their homeserver accounts,
+and perform password resets, make sure that Synapse is configured with a working
+email server in the [`email` configuration
+section](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#email)
+(including, at a minimum, a `notif_from` setting.)
+
+Specifying an `email` setting under `account_threepid_delegates` will now cause
+an error at startup.
+
 # Upgrading to v1.64.0
 
 ## Deprecation of the ability to delegate e-mail verification to identity servers
diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index cc72966823..8ae018e628 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -2182,7 +2182,10 @@ their account.
 by the Matrix Identity Service API
 [specification](https://matrix.org/docs/spec/identity_service/latest).)
 
-*Updated in Synapse 1.64.0*: The `email` option is deprecated.
+*Deprecated in Synapse 1.64.0*: The `email` option is deprecated.
+
+*Removed in Synapse 1.66.0*: The `email` option has been removed.
+If present, Synapse will report a configuration error on startup.
 
 Example configuration:
 ```yaml
diff --git a/pyproject.toml b/pyproject.toml
index 9e59470ac8..745b6067aa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,7 @@ skip_gitignore = true
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.65.0"
+version = "1.66.0rc1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "Apache-2.0"
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index d98012adeb..68993d91a9 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -44,7 +44,6 @@ from synapse.app._base import (
     register_start,
 )
 from synapse.config._base import ConfigError, format_config_error
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.server import ListenerConfig
 from synapse.federation.transport.server import TransportLayerServer
@@ -202,7 +201,7 @@ class SynapseHomeServer(HomeServer):
                 }
             )
 
-            if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            if self.config.email.can_verify_email:
                 from synapse.rest.synapse.client.password_reset import (
                     PasswordResetSubmitTokenResource,
                 )
diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index 66a6dbf1fe..a3af35b7c4 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -18,7 +18,6 @@
 import email.utils
 import logging
 import os
-from enum import Enum
 from typing import Any
 
 import attr
@@ -136,40 +135,22 @@ class EmailConfig(Config):
 
         self.email_enable_notifs = email_config.get("enable_notifs", False)
 
-        self.threepid_behaviour_email = (
-            # Have Synapse handle the email sending if account_threepid_delegates.email
-            # is not defined
-            # msisdn is currently always remote while Synapse does not support any method of
-            # sending SMS messages
-            ThreepidBehaviour.REMOTE
-            if self.root.registration.account_threepid_delegate_email
-            else ThreepidBehaviour.LOCAL
-        )
-
         if config.get("trust_identity_server_for_password_resets"):
             raise ConfigError(
-                'The config option "trust_identity_server_for_password_resets" has been removed.'
-                "Please consult the configuration manual at docs/usage/configuration/config_documentation.md for "
-                "details and update your config file."
+                'The config option "trust_identity_server_for_password_resets" '
+                "is no longer supported. Please remove it from the config file."
             )
 
-        self.local_threepid_handling_disabled_due_to_email_config = False
-        if (
-            self.threepid_behaviour_email == ThreepidBehaviour.LOCAL
-            and email_config == {}
-        ):
-            # We cannot warn the user this has happened here
-            # Instead do so when a user attempts to reset their password
-            self.local_threepid_handling_disabled_due_to_email_config = True
-
-            self.threepid_behaviour_email = ThreepidBehaviour.OFF
+        # If we have email config settings, assume that we can verify ownership of
+        # email addresses.
+        self.can_verify_email = email_config != {}
 
         # Get lifetime of a validation token in milliseconds
         self.email_validation_token_lifetime = self.parse_duration(
             email_config.get("validation_token_lifetime", "1h")
         )
 
-        if self.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.can_verify_email:
             missing = []
             if not self.email_notif_from:
                 missing.append("email.notif_from")
@@ -360,18 +341,3 @@ class EmailConfig(Config):
                     "Config option email.invite_client_location must be a http or https URL",
                     path=("email", "invite_client_location"),
                 )
-
-
-class ThreepidBehaviour(Enum):
-    """
-    Enum to define the behaviour of Synapse with regards to when it contacts an identity
-    server for 3pid registration and password resets
-
-    REMOTE = use an external server to send tokens
-    LOCAL = send tokens ourselves
-    OFF = disable registration via 3pid and password resets
-    """
-
-    REMOTE = "remote"
-    LOCAL = "local"
-    OFF = "off"
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 01fb0331bc..a888d976f2 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import argparse
-import logging
 from typing import Any, Optional
 
 from synapse.api.constants import RoomCreationPreset
@@ -21,15 +20,11 @@ from synapse.config._base import Config, ConfigError
 from synapse.types import JsonDict, RoomAlias, UserID
 from synapse.util.stringutils import random_string_with_symbols, strtobool
 
-logger = logging.getLogger(__name__)
-
-LEGACY_EMAIL_DELEGATE_WARNING = """\
-Delegation of email verification to an identity server is now deprecated. To
+NO_EMAIL_DELEGATE_ERROR = """\
+Delegation of email verification to an identity server is no longer supported. To
 continue to allow users to add email addresses to their accounts, and use them for
 password resets, configure Synapse with an SMTP server via the `email` setting, and
 remove `account_threepid_delegates.email`.
-
-This will be an error in a future version.
 """
 
 
@@ -64,9 +59,7 @@ class RegistrationConfig(Config):
 
         account_threepid_delegates = config.get("account_threepid_delegates") or {}
         if "email" in account_threepid_delegates:
-            logger.warning(LEGACY_EMAIL_DELEGATE_WARNING)
-
-        self.account_threepid_delegate_email = account_threepid_delegates.get("email")
+            raise ConfigError(NO_EMAIL_DELEGATE_ERROR)
         self.account_threepid_delegate_msisdn = account_threepid_delegates.get("msisdn")
         self.default_identity_server = config.get("default_identity_server")
         self.allow_guest_access = config.get("allow_guest_access", False)
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index e5afe84df9..9571d461c8 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -26,7 +26,6 @@ from synapse.api.errors import (
     SynapseError,
 )
 from synapse.api.ratelimiting import Ratelimiter
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.http import RequestTimedOutError
 from synapse.http.client import SimpleHttpClient
 from synapse.http.site import SynapseRequest
@@ -416,48 +415,6 @@ class IdentityHandler:
 
         return session_id
 
-    async def request_email_token(
-        self,
-        id_server: str,
-        email: str,
-        client_secret: str,
-        send_attempt: int,
-        next_link: Optional[str] = None,
-    ) -> JsonDict:
-        """
-        Request an external server send an email on our behalf for the purposes of threepid
-        validation.
-
-        Args:
-            id_server: The identity server to proxy to
-            email: The email to send the message to
-            client_secret: The unique client_secret sends by the user
-            send_attempt: Which attempt this is
-            next_link: A link to redirect the user to once they submit the token
-
-        Returns:
-            The json response body from the server
-        """
-        params = {
-            "email": email,
-            "client_secret": client_secret,
-            "send_attempt": send_attempt,
-        }
-        if next_link:
-            params["next_link"] = next_link
-
-        try:
-            data = await self.http_client.post_json_get_json(
-                id_server + "/_matrix/identity/api/v1/validate/email/requestToken",
-                params,
-            )
-            return data
-        except HttpResponseException as e:
-            logger.info("Proxied requestToken failed: %r", e)
-            raise e.to_synapse_error()
-        except RequestTimedOutError:
-            raise SynapseError(500, "Timed out contacting identity server")
-
     async def requestMsisdnToken(
         self,
         id_server: str,
@@ -531,18 +488,7 @@ class IdentityHandler:
         validation_session = None
 
         # Try to validate as email
-        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
-            # Remote emails will only be used if a valid identity server is provided.
-            assert (
-                self.hs.config.registration.account_threepid_delegate_email is not None
-            )
-
-            # Ask our delegated email identity server
-            validation_session = await self.threepid_from_creds(
-                self.hs.config.registration.account_threepid_delegate_email,
-                threepid_creds,
-            )
-        elif self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.hs.config.email.can_verify_email:
             # Get a validated session matching these details
             validation_session = await self.store.get_threepid_validation_session(
                 "email", client_secret, sid=sid, validated=True
diff --git a/synapse/handlers/ui_auth/checkers.py b/synapse/handlers/ui_auth/checkers.py
index 05cebb5d4d..a744d68c64 100644
--- a/synapse/handlers/ui_auth/checkers.py
+++ b/synapse/handlers/ui_auth/checkers.py
@@ -19,7 +19,6 @@ from twisted.web.client import PartialDownloadError
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes, LoginError, SynapseError
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.util import json_decoder
 
 if TYPE_CHECKING:
@@ -153,7 +152,7 @@ class _BaseThreepidAuthChecker:
 
         logger.info("Getting validated threepid. threepidcreds: %r", (threepid_creds,))
 
-        # msisdns are currently always ThreepidBehaviour.REMOTE
+        # msisdns are currently always verified via the IS
         if medium == "msisdn":
             if not self.hs.config.registration.account_threepid_delegate_msisdn:
                 raise SynapseError(
@@ -164,18 +163,7 @@ class _BaseThreepidAuthChecker:
                 threepid_creds,
             )
         elif medium == "email":
-            if (
-                self.hs.config.email.threepid_behaviour_email
-                == ThreepidBehaviour.REMOTE
-            ):
-                assert self.hs.config.registration.account_threepid_delegate_email
-                threepid = await identity_handler.threepid_from_creds(
-                    self.hs.config.registration.account_threepid_delegate_email,
-                    threepid_creds,
-                )
-            elif (
-                self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL
-            ):
+            if self.hs.config.email.can_verify_email:
                 threepid = None
                 row = await self.store.get_threepid_validation_session(
                     medium,
@@ -227,10 +215,7 @@ class EmailIdentityAuthChecker(UserInteractiveAuthChecker, _BaseThreepidAuthChec
         _BaseThreepidAuthChecker.__init__(self, hs)
 
     def is_enabled(self) -> bool:
-        return self.hs.config.email.threepid_behaviour_email in (
-            ThreepidBehaviour.REMOTE,
-            ThreepidBehaviour.LOCAL,
-        )
+        return self.hs.config.email.can_verify_email
 
     async def check_auth(self, authdict: dict, clientip: str) -> Any:
         return await self._check_threepid("email", authdict)
diff --git a/synapse/rest/client/account.py b/synapse/rest/client/account.py
index 9041e29d6c..1f9a8ccc23 100644
--- a/synapse/rest/client/account.py
+++ b/synapse/rest/client/account.py
@@ -29,7 +29,6 @@ from synapse.api.errors import (
     SynapseError,
     ThreepidValidationError,
 )
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.handlers.ui_auth import UIAuthSessionDataConstants
 from synapse.http.server import HttpServer, finish_request, respond_with_html
 from synapse.http.servlet import (
@@ -68,7 +67,7 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
         self.config = hs.config
         self.identity_handler = hs.get_identity_handler()
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.config.email.can_verify_email:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -77,11 +76,10 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
-                logger.warning(
-                    "User password resets have been disabled due to lack of email config"
-                )
+        if not self.config.email.can_verify_email:
+            logger.warning(
+                "User password resets have been disabled due to lack of email config"
+            )
             raise SynapseError(
                 400, "Email-based password resets have been disabled on this server"
             )
@@ -117,35 +115,20 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
-            assert self.hs.config.registration.account_threepid_delegate_email
-
-            # Have the configured identity server handle the request
-            ret = await self.identity_handler.request_email_token(
-                self.hs.config.registration.account_threepid_delegate_email,
-                body.email,
-                body.client_secret,
-                body.send_attempt,
-                body.next_link,
-            )
-        else:
-            # Send password reset emails from Synapse
-            sid = await self.identity_handler.send_threepid_validation(
-                body.email,
-                body.client_secret,
-                body.send_attempt,
-                self.mailer.send_password_reset_mail,
-                body.next_link,
-            )
-
-            # Wrap the session id in a JSON object
-            ret = {"sid": sid}
-
+        # Send password reset emails from Synapse
+        sid = await self.identity_handler.send_threepid_validation(
+            body.email,
+            body.client_secret,
+            body.send_attempt,
+            self.mailer.send_password_reset_mail,
+            body.next_link,
+        )
         threepid_send_requests.labels(type="email", reason="password_reset").observe(
             body.send_attempt
         )
 
-        return 200, ret
+        # Wrap the session id in a JSON object
+        return 200, {"sid": sid}
 
 
 class PasswordRestServlet(RestServlet):
@@ -340,7 +323,7 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
         self.identity_handler = hs.get_identity_handler()
         self.store = self.hs.get_datastores().main
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.config.email.can_verify_email:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -349,11 +332,10 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
-                logger.warning(
-                    "Adding emails have been disabled due to lack of an email config"
-                )
+        if not self.config.email.can_verify_email:
+            logger.warning(
+                "Adding emails have been disabled due to lack of an email config"
+            )
             raise SynapseError(
                 400,
                 "Adding an email to your account is disabled on this server",
@@ -391,35 +373,21 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
-            assert self.hs.config.registration.account_threepid_delegate_email
-
-            # Have the configured identity server handle the request
-            ret = await self.identity_handler.request_email_token(
-                self.hs.config.registration.account_threepid_delegate_email,
-                body.email,
-                body.client_secret,
-                body.send_attempt,
-                body.next_link,
-            )
-        else:
-            # Send threepid validation emails from Synapse
-            sid = await self.identity_handler.send_threepid_validation(
-                body.email,
-                body.client_secret,
-                body.send_attempt,
-                self.mailer.send_add_threepid_mail,
-                body.next_link,
-            )
-
-            # Wrap the session id in a JSON object
-            ret = {"sid": sid}
+        # Send threepid validation emails from Synapse
+        sid = await self.identity_handler.send_threepid_validation(
+            body.email,
+            body.client_secret,
+            body.send_attempt,
+            self.mailer.send_add_threepid_mail,
+            body.next_link,
+        )
 
         threepid_send_requests.labels(type="email", reason="add_threepid").observe(
             body.send_attempt
         )
 
-        return 200, ret
+        # Wrap the session id in a JSON object
+        return 200, {"sid": sid}
 
 
 class MsisdnThreepidRequestTokenRestServlet(RestServlet):
@@ -512,24 +480,18 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
         self.config = hs.config
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.config.email.can_verify_email:
             self._failure_email_template = (
                 self.config.email.email_add_threepid_template_failure_html
             )
 
     async def on_GET(self, request: Request) -> None:
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
-                logger.warning(
-                    "Adding emails have been disabled due to lack of an email config"
-                )
-            raise SynapseError(
-                400, "Adding an email to your account is disabled on this server"
+        if not self.config.email.can_verify_email:
+            logger.warning(
+                "Adding emails have been disabled due to lack of an email config"
             )
-        elif self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
             raise SynapseError(
-                400,
-                "This homeserver is not validating threepids.",
+                400, "Adding an email to your account is disabled on this server"
             )
 
         sid = parse_string(request, "sid", required=True)
diff --git a/synapse/rest/client/register.py b/synapse/rest/client/register.py
index 1b953d3fa0..20bab20c8f 100644
--- a/synapse/rest/client/register.py
+++ b/synapse/rest/client/register.py
@@ -31,7 +31,6 @@ from synapse.api.errors import (
 )
 from synapse.api.ratelimiting import Ratelimiter
 from synapse.config import ConfigError
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.ratelimiting import FederationRatelimitSettings
 from synapse.config.server import is_threepid_reserved
@@ -74,7 +73,7 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
         self.identity_handler = hs.get_identity_handler()
         self.config = hs.config
 
-        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.hs.config.email.can_verify_email:
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email.email_app_name,
@@ -83,13 +82,10 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
             )
 
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
-        if self.hs.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if (
-                self.hs.config.email.local_threepid_handling_disabled_due_to_email_config
-            ):
-                logger.warning(
-                    "Email registration has been disabled due to lack of email config"
-                )
+        if not self.hs.config.email.can_verify_email:
+            logger.warning(
+                "Email registration has been disabled due to lack of email config"
+            )
             raise SynapseError(
                 400, "Email-based registration has been disabled on this server"
             )
@@ -138,35 +134,21 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
-            assert self.hs.config.registration.account_threepid_delegate_email
-
-            # Have the configured identity server handle the request
-            ret = await self.identity_handler.request_email_token(
-                self.hs.config.registration.account_threepid_delegate_email,
-                email,
-                client_secret,
-                send_attempt,
-                next_link,
-            )
-        else:
-            # Send registration emails from Synapse,
-            # wrapping the session id in a JSON object.
-            ret = {
-                "sid": await self.identity_handler.send_threepid_validation(
-                    email,
-                    client_secret,
-                    send_attempt,
-                    self.mailer.send_registration_mail,
-                    next_link,
-                )
-            }
+        # Send registration emails from Synapse
+        sid = await self.identity_handler.send_threepid_validation(
+            email,
+            client_secret,
+            send_attempt,
+            self.mailer.send_registration_mail,
+            next_link,
+        )
 
         threepid_send_requests.labels(type="email", reason="register").observe(
             send_attempt
         )
 
-        return 200, ret
+        # Wrap the session id in a JSON object
+        return 200, {"sid": sid}
 
 
 class MsisdnRegisterRequestTokenRestServlet(RestServlet):
@@ -260,7 +242,7 @@ class RegistrationSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
 
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+        if self.config.email.can_verify_email:
             self._failure_email_template = (
                 self.config.email.email_registration_template_failure_html
             )
@@ -270,11 +252,10 @@ class RegistrationSubmitTokenServlet(RestServlet):
             raise SynapseError(
                 400, "This medium is currently not supported for registration"
             )
-        if self.config.email.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if self.config.email.local_threepid_handling_disabled_due_to_email_config:
-                logger.warning(
-                    "User registration via email has been disabled due to lack of email config"
-                )
+        if not self.config.email.can_verify_email:
+            logger.warning(
+                "User registration via email has been disabled due to lack of email config"
+            )
             raise SynapseError(
                 400, "Email-based registration is disabled on this server"
             )
diff --git a/synapse/rest/synapse/client/password_reset.py b/synapse/rest/synapse/client/password_reset.py
index 6ac9dbc7c9..b9402cfb75 100644
--- a/synapse/rest/synapse/client/password_reset.py
+++ b/synapse/rest/synapse/client/password_reset.py
@@ -17,7 +17,6 @@ from typing import TYPE_CHECKING, Tuple
 from twisted.web.server import Request
 
 from synapse.api.errors import ThreepidValidationError
-from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.http.server import DirectServeHtmlResource
 from synapse.http.servlet import parse_string
 from synapse.util.stringutils import assert_valid_client_secret
@@ -46,9 +45,6 @@ class PasswordResetSubmitTokenResource(DirectServeHtmlResource):
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
 
-        self._local_threepid_handling_disabled_due_to_email_config = (
-            hs.config.email.local_threepid_handling_disabled_due_to_email_config
-        )
         self._confirmation_email_template = (
             hs.config.email.email_password_reset_template_confirmation_html
         )
@@ -59,8 +55,8 @@ class PasswordResetSubmitTokenResource(DirectServeHtmlResource):
             hs.config.email.email_password_reset_template_failure_html
         )
 
-        # This resource should not be mounted if threepid behaviour is not LOCAL
-        assert hs.config.email.threepid_behaviour_email == ThreepidBehaviour.LOCAL
+        # This resource should only be mounted if email validation is enabled
+        assert hs.config.email.can_verify_email
 
     async def _async_render_GET(self, request: Request) -> Tuple[int, bytes]:
         sid = parse_string(request, "sid", required=True)
diff --git a/tests/rest/client/test_register.py b/tests/rest/client/test_register.py
index ab4277dd31..b781875d52 100644
--- a/tests/rest/client/test_register.py
+++ b/tests/rest/client/test_register.py
@@ -586,9 +586,9 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
                 "require_at_registration": True,
             },
             "account_threepid_delegates": {
-                "email": "https://id_server",
                 "msisdn": "https://id_server",
             },
+            "email": {"notif_from": "Synapse <synapse@example.com>"},
         }
     )
     def test_advertised_flows_captcha_and_terms_and_3pids(self) -> None: