Currently the Message-IDs we send out for outbound email
are not unique; for a post they look like:
topic/TOPIC_ID/POST_ID@HOST
And for a topic they look like:
topic/TOPIC_ID@HOST
This commit changes the outbound Message-IDs to also have
a random suffix before the host, so the new format is
like this:
topic/TOPIC_ID/POST_ID.RANDOM_SUFFIX@HOST
Or:
topic/TOPIC_ID.RANDOM_SUFFIX@HOST
This should help with email deliverability. This change
is backwards-compatible, the old Message-ID format will
still be recognized in the mail receiver flow, so people
will still be able to reply using Message-IDs, In-Reply-To,
and References headers that have already been sent.
This commit also refactors Message-ID related logic
to a central location, and adds judicious amounts of
tests and documentation.
This overhauls the user interface for the group email settings management, aiming to make it a lot easier to test the settings entered and confirm they are correct before proceeding. We do this by forcing the user to test the settings before they can be saved to the database. It also includes some quality of life improvements around setting up IMAP and SMTP for our first supported provider, GMail. This PR does not remove the old group email config, that will come in a subsequent PR. This is related to https://meta.discourse.org/t/imap-support-for-group-inboxes/160588 so read that if you would like more backstory.
### UI
Both site settings of `enable_imap` and `enable_smtp` must be true to test this. You must enable SMTP first to enable IMAP.
You can prefill the SMTP settings with GMail configuration. To proceed with saving these settings you must test them, which is handled by the EmailSettingsValidator.
If there is an issue with the configuration or credentials a meaningful error message should be shown.
IMAP settings must also be validated when IMAP is enabled, before saving.
When saving IMAP, we fetch the mailboxes for that account and populate them. This mailbox must be selected and saved for IMAP to work (the feature acts as though it is disabled until the mailbox is selected and saved):
### Database & Backend
This adds several columns to the Groups table. The purpose of this change is to make it much more explicit that SMTP/IMAP is enabled for a group, rather than relying on settings not being null. Also included is an UPDATE query to backfill these columns. These columns are automatically filled when updating the group.
For GMail, we now filter the mailboxes returned. This is so users cannot use a mailbox like Sent or Trash for syncing, which would generally be disastrous.
There is a new group endpoint for testing email settings. This may be useful in the future for other places in our UI, at which point it can be extracted to a more generic endpoint or module to be included.
Over the years we accrued many spelling mistakes in the code base.
This PR attempts to fix spelling mistakes and typos in all areas of the code that are extremely safe to change
- comments
- test descriptions
- other low risk areas
Improvements to make console access to IncomingEmail more pleasant, and stopping certain IMAP logs from landing in the DB because they just create too much noise,
This should make it easier to track down how the incoming email was created, which is one of four locations:
The POP3 poller (which picks up reply via email replies)
The admin email controller #handle_mail (which is where hosted mail is sent)
The IMAP sync tool
The group SMTP mailer, which sends emails when replying to IMAP topics, pre-emptively creating IncomingEmail records to avoid double syncing
This PR fixes a race condition with the IMAP notification code. In the `Email::Receiver` we call the `NewPostManager` to create the post and enqueue jobs and sends alerts via `PostAlerter`. However, if the post alerter reaches the `notify_pm_users` and the `group_notifying_via_smtp` method _before_ the incoming email is updated with the post and topic, we unnecessarily send a notification to the person who just posted. The result of this is that the IMAP syncer re-imports the email sent to the user about their own post, which looks like this in the group inbox:
To fix this, we skip the jobs enqueued by `NewPostManager` and only enqueue them with `PostJobsEnqueuer` manually _after_ the incoming email record has been updated with the post and topic.
Other improvements:
* Moved code to calculate email addresses from `IncomingEmail` records into the topic, with a group passed in, for easier testing and debugging. It is not the responsibility of the post alerter to figure this stuff out.
* Add shortcut methods on `IncomingEmail` to split or provide an empty array for to and cc addresses to avoid repetition.
This PR adds functionality for the IMAP sync code to detect if a UID that is missing from the mail group mailbox is in the Spam/Junk folder for the mail account, and if so delete the associated Discourse topic. This is identical to what we do for emails that are moved for Trash.
If an email is missing but not in Spam or Trash, then we mark the incoming email record with imap_missing: true. This may be used in future to further filter or identify these emails, and perhaps go hunting for them in the email account in bulk.
Note: This adds some code duplication because the trash and spam email detection and handling is very similar. I intend to do more refactors/improvements to the IMAP sync code in time because there is a lot of room for improvement.
Convert all IMAP logging to write to a database table for easier inspection. These logs are cleaned up daily if they are > 5 days old.
Logs can easily be watched in dev by setting DISCOURSE_DEV_LOG_LEVEL=\"debug\" and running tail -f development.log | grep IMAP
Previously we did an early return if either SiteSetting.tagging_enabled or SiteSetting.allow_staff_to_tag_pms was false when updating the email on the IMAP server -- however this also stopped us from archiving or deleting emails if either of these were disabled.
Adds functionality to reflect topic delete in Discourse to IMAP inbox (Gmail only for now) and reflecting Gmail deletes in Discourse.
Adding lots of tests, various refactors and code improvements.
When Discourse topic is destroyed in PostDestroyer mark the topic incoming email as imap_sync: true, and do the opposite when post is recovered.
* Fixed an issue I introduced in the last PR where I am just archiving everything regardless of whether it is actually archived in Discourse man_facepalming
* Refactor group list_mailboxes IMAP code to use providers, add specs, and add provider code to get the correct prodivder
Adds a imap_group_id column to IncomingEmail to deal with an issue where we were trying to update emails in the mailbox, calling IncomingEmail.where(imap_sync: true). However UID and UIDVALIDITY could be the same across accounts. So if group A used IMAP details for Gmail account A, and group B used IMAP details for Gmail account B, and both tried to sync changes to an email with UID of 3 (e.g. changing Labels), one account could affect the other. This even applied to Archiving!
Also in this PR:
* Fix error occurring if we do a uid_fetch and no emails are returned
* Allow for creating labels within the target mailbox (previously we would not do this, only use existing labels)
* Improve consistency for log messages
* Add specs for generic IMAP provider (Gmail specs still to come)
* Add custom archiving support for Gmail
* Only use Message-ID for uniqueness of IncomingEmail if it was generated by us
* Various refactors and improvements
Martin Brennan
Dan Ungureanu
Josh Soref