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.
Sometimes, a user may have a malformed email such as
`test@test.com<mailto:test@test.com` their email address,
and as a topic participant will be included as a CC email
when sending a GroupSmtpEmail. This causes the CC parsing to
fail and further down the line in Email::Sender the code
to check the CC addresses expects an array but gets a string
instead because of the parse failure.
Instead, we can just check if the CC addresses are valid
and drop them if they are not in the GroupSmtpEmail job.
This commit removes the recipient's username from the
respond to / participants list that is shown at the bottom
of user notification emails. For example if the recipient's
username was jsmith, and there were participants ljones and
bmiller, we currently show this:
> "reply to this email to respond to jsmith, ljones, bmiller"
or
> "Participants: jsmith, ljones, bmiller"
However this is a bit redundant, as you are not replying to
yourself here if you are the recipient user. So we omit the
recipient user's username from this list, which is only used
in the text of the email and not elsewhere.
We now use the group's full name in group SMTP emails, so we are dropping the via #{site_name}. If group owners still want this they can just change the full name of the group.
This PR fixes a couple of issues related to group SMTP:
1. When running the group SMTP job, we were exiting early if the email was for the OP because of an IMAP race condition. However this causes issues when replying as a new topic for an existing SMTP topic, as the recipient does not get the OP email which can cause threading problems.
2. When sending emails for a new topic spun out like the issue in 1., we are not maintaining the original subject/topic title because that is based on the incoming email record, which we were not doing because the group SMTP email was never sent because of issue 1.
Skip group SMTP email (and add log) if:
* topic is deleted
* post is deleted
* smtp has been disabled for the group
Skip without log if:
* enable_smtp site setting is false
* disable_emails site setting is yes
Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
We do not want to show the In Reply To section of the
group SMTP email template, it is similar to Context Posts
which we removed and is unnecessary.
This PR also removes the link to staged user profiles in
the email; their email addresses will just be converted
to regular mailto: links.
This PR makes several changes to the group SMTP email contents to make it look more like a support inbox message.
* Remove the context posts, they only add clutter to the email and replies
* Display email addresses of staged users instead of odd generated usernames
* Add a "please reply above this line" message to sent emails
This PR backtracks a fair bit on this one https://github.com/discourse/discourse/pull/13220/files.
Instead of sending the group SMTP email for each user via `UserNotifications`, we are changing to send only one email with the existing `Jobs::GroupSmtpEmail` job and `GroupSmtpMailer`. We are changing this job and mailer along with `PostAlerter` to make the first topic allowed user the `to_address` for the email and any other `topic_allowed_users` to be the CC address on the email. This is to cut down on emails sent via SMTP, which is subject to daily limits from providers such as Gmail. We log these details in the `EmailLog` table now.
In addition to this, we have changed `PostAlerter` to no longer rely on incoming email email addresses for sending the `GroupSmtpEmail` job. This was unreliable as a user's email could have changed in the meantime. Also it was a little overcomplicated to use the incoming email records -- it is far simpler to reason about to just use topic allowed users.
This also adds a fix to include cc_addresses in the EmailLog.addressed_to_user scope.
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
Fixes a rare race condition causing the `Imap::Sync` class to create an incoming email and associated post/topic, which then kicks off the PostAlerter to notify others in the PM about a reply in the topic, but for the OP which is not necessary (because the person emailing the IMAP inbox already knows about the OP). Basically, we should never be sending the group SMTP email for the first post in a topic.
Also in this PR:
* Custom attribute accessors for the to/from/cc addresses on `IncomingEmail`, to parse them from an array to a joined string so the logic for this is only in one place.
* Store extra detail against the `IncomingEmail` created in `GroupSmtpMailer`
* regex test Mail header Reply-To as string instead of Field, which fixes `warning: deprecated Object#=~ is called on Mail::Field; it always returns nil`
* Add DEBUG_IMAP to log all IMAP logs as warnings for easier debugging
* Changed the Rails logging to `ImapSyncLog` in the `GroupSmtpMailer`
There is a site setting reply_by_email_enabled which when combined with reply_by_email_address creates a Reply-To header in emails in the format "test+%{reply_key}@test.com" along with a PostReplyKey record, so when replying Discourse knows where to route the reply.
However this conflicts with the IMAP implementation. Since we are sending the email for a group via SMTP and from their actual email account, we want all replys to go to that email account as well so the IMAP sync job can pick them up and put them in the correct place. So if the group has IMAP enabled and configured, then the reply-to header will be correct.
This PR also makes a further fix to 64b0b50 by using the correct recipient user for the PostReplyKey record. If the post user is used we encounter this error:
if destination.user_id != user.id && !forwarded_reply_key?(destination, user)
raise ReplyUserNotMatchingError, "post_reply_key.user_id => #{destination.user_id.inspect}, user.id => #{user.id.inspect}"
end
This is because the user above is found from the from_address, but the destination which is the PostReplyKey is made by the post.user, which will be different people.
Our Email::Sender class accepts an optional user argument, which is used to create a PostReplyKey record when present. This record is used to sub out the %{reply_key} placeholder in the Reply-To mail header, so if we do not pass in the user we get a broken Reply-To header.
This is especially problematic in the IMAP group SMTP situation, because these emails go to customers that we are replying to, and when they reply to us the email bounces! This fixes the issue by passing user to the Email::Sender when sending a group_smtp email but there is still more to do in another PR.
This Email::Sender optional user is a bit of a footgun IMO, especially because most of the time we use it there is a user we can source. I would like to do another PR for this after this one to make the parameter not optional, so we don't end up with these reply issues down the line again.
Martin Brennan