feat: add email forwarding message channel (#19535)

## Summary

- Add email forwarding as a new message channel type, allowing users to
forward emails from addresses like `support@mycompany.com` into Twenty
- Inbound emails arrive via S3 (SES → S3 bucket), are polled by a cron
job, parsed, routed to the correct workspace/channel, and persisted as
messages
- Dedicated settings page at `/settings/accounts/new-email-forwarding`
where users provide their source email handle and receive a unique
forwarding address
- Forwarding channels bypass the IMAP/mailbox sync state machine — they
skip cron-driven sync, relaunch, and message-list-fetch lifecycle stages
- Forwarding address section shown at the top of the Emails settings
page so users can find/copy their addresses after initial setup
- Tab names for forwarding channels display the user-provided handle
(e.g. `support@mycompany.com`) instead of the internal routing address
- Shared utilities extracted from IMAP driver: `extractThreadId`,
`extractParticipants`, `extractAddresses` to avoid code duplication
- Uses the existing S3 bucket (STORAGE_S3_*) with `inbound-email/`
prefix — no separate bucket needed
- Feature gated behind `isEmailForwardingEnabled` client config
(requires `INBOUND_EMAIL_DOMAIN` + S3 storage)

## New backend modules

- `InboundEmailS3ClientProvider` — lazy-initialized S3 client using
existing storage config
- `InboundEmailStorageService` — S3 operations (get, move to
processed/unmatched/failed)
- `InboundEmailParserService` — RFC 822 parsing via `postal-mime`,
builds `MessageWithParticipants`
- `InboundEmailImportService` — orchestrates download → parse → route →
persist → archive
- `MessagingInboundEmailPollCronJob` — polls S3 `incoming/` prefix,
enqueues import jobs
- `CreateEmailForwardingChannelInput` DTO — accepts user-provided
`handle`

## New frontend components

- `SettingsAccountsNewEmailForwardingChannel` — dedicated page with
handle input form + forwarding address result
- `SettingsAccountsEmailForwardingSection` — forwarding address list on
the Emails settings page
- `useConnectedAccountHandleMap` — shared hook for account ID → handle
lookup
- `useCreateEmailForwardingChannel` — mutation hook accepting handle
parameter

## Test plan

- [x] 17 unit tests for inbound email import service (all outcomes:
imported, unmatched, loop_dropped, unconfigured, parse_failed,
persist_failed)
- [x] 16 tests for `computeSyncStatus` including EMAIL_FORWARDING cases
- [x] 11 tests for `extractEnvelopeRecipient` utility
- [x] TypeScript typechecks pass for both twenty-server and twenty-front
- [x] Lint passes for both packages
- [ ] Manual: create forwarding channel, verify forwarding address
generated
- [ ] Manual: send email to forwarding address, verify it appears in
Twenty

https://claude.ai/code/session_01KpyF6p4cUEnuaT4h8DP5Pm

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>
Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: neo773 <62795688+neo773@users.noreply.github.com>
Co-authored-by: neo773 <neo773@protonmail.com>

packages/twenty-server/src/database/commands/upgrade-version-command/2-4/2-4-instance-command-fast-1778256809018-add-email-group-channel-type.ts

@@ -0,0 +1,35 @@
+import { QueryRunner } from 'typeorm';
+
+import { RegisteredInstanceCommand } from 'src/engine/core-modules/upgrade/decorators/registered-instance-command.decorator';
+import { FastInstanceCommand } from 'src/engine/core-modules/upgrade/interfaces/fast-instance-command.interface';
+
+@RegisteredInstanceCommand('2.4.0', 1778256809018)
+export class AddEmailGroupChannelTypeFastInstanceCommand
+  implements FastInstanceCommand
+{
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      'ALTER TYPE "core"."messageChannel_type_enum" RENAME TO "messageChannel_type_enum_old"',
+    );
+    await queryRunner.query(
+      "CREATE TYPE \"core\".\"messageChannel_type_enum\" AS ENUM('EMAIL', 'SMS', 'EMAIL_GROUP')",
+    );
+    await queryRunner.query(
+      'ALTER TABLE "core"."messageChannel" ALTER COLUMN "type" TYPE "core"."messageChannel_type_enum" USING "type"::"text"::"core"."messageChannel_type_enum"',
+    );
+    await queryRunner.query('DROP TYPE "core"."messageChannel_type_enum_old"');
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      'CREATE TYPE "core"."messageChannel_type_enum_old" AS ENUM(\'EMAIL\', \'SMS\')',
+    );
+    await queryRunner.query(
+      'ALTER TABLE "core"."messageChannel" ALTER COLUMN "type" TYPE "core"."messageChannel_type_enum_old" USING "type"::"text"::"core"."messageChannel_type_enum_old"',
+    );
+    await queryRunner.query('DROP TYPE "core"."messageChannel_type_enum"');
+    await queryRunner.query(
+      'ALTER TYPE "core"."messageChannel_type_enum_old" RENAME TO "messageChannel_type_enum"',
+    );
+  }
+}

packages/twenty-server/src/database/commands/upgrade-version-command/instance-commands.constant.ts

@@ -29,6 +29,7 @@ import { TransformApplicationVariableToSyncableEntityFastInstanceCommand } from
 import { AddToolAndWorkflowActionTriggerSettingsFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-3/2-3-instance-command-fast-1797000001000-add-tool-and-workflow-action-trigger-settings';
 import { BackfillApplicationVariableUniversalIdentifierSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-3/2-3-instance-command-slow-1777966965588-backfill-application-variable-universal-identifier';
 import { MigrateToolTriggerSettingsSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-3/2-3-instance-command-slow-1797000002000-migrate-tool-trigger-settings';
+import { AddEmailGroupChannelTypeFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-4/2-4-instance-command-fast-1778256809018-add-email-group-channel-type';
 
 export const INSTANCE_COMMANDS = [
   AddViewFieldGroupIdIndexOnViewFieldFastInstanceCommand,
@@ -60,4 +61,5 @@ export const INSTANCE_COMMANDS = [
   RemoveUserDefaultAvatarUrlFastInstanceCommand,
   TransformApplicationVariableToSyncableEntityFastInstanceCommand,
   BackfillApplicationVariableUniversalIdentifierSlowInstanceCommand,
+  AddEmailGroupChannelTypeFastInstanceCommand,
 ];