Since 3b13f1146b the email threading
in mail clients has been broken, because the random suffix meant
that the References header would always be different for non-group
SMTP email notifications sent out.
This commit fixes the issue by always using the "canonical" topic
reference ID inside the References header in the format:
topic/TOPIC_ID@HOST
Which was the old format. We also add the References header to
notifications sent for the first post arriving, so the threading
works for subsequent emails. The Message-ID header is still random
as per the previous change.
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.
* FIX: Remove List-Post email header
This header is used for mailing lists and can confuse some email clients
such as Thunderbird to display wrong replying options.
* FIX: Replace reply_key in email custom headers
Admins can add custom email headers from site settings. Email sender
will try to replace the reply key if %{reply_key} exists or remove the
header if a reply key does not exist.
Inlining secure images with the same name was not possible because they
were indexed by filename. If an email contained two files with the same
name, only the first image was used for both of them. The other file
was still attached to the email.
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 adds the following columns to EmailLog:
* cc_addresses
* cc_user_ids
* topic_id
* raw
This is to bring the EmailLog table closer in parity to
IncomingEmail so it can be better utilized for Group SMTP
and IMAP mailing.
The raw column contains the full content of the outbound email,
but _only_ if the new hidden site setting
enable_raw_outbound_email_logging is enabled. Most sites do not
need it, and it's mostly required for IMAP and SMTP sending.
In the next pull request, there will be a migration to backfill
topic_id on the EmailLog table, at which point we can remove the
topic fallback method on EmailLog.
When we are emailing people from a group inbox, we are having
a PM conversation with them, as a support account would. In this
case mailing list headers do not make sense. It is not like a forum
topic where you may have tens or hundreds of participants -- it is a
conversation between the group and a small handful of people
directly contacting the group, often just one person.
The only header left in tact was List-Unsubsribe which is important
for letting people opt out to notifications.
Adds a new `smtp_group_id` column to `EmailLog` which is filled in if the mail `from_address` matches a group's `email_username`. This is for easier debugging, so we know which emails have been sent via group SMTP.
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`
When calculating whether the attached uploads went over the SiteSetting.email_total_attachment_size_limit_kb.kilobytes limit, we were using the original_upload for the calculation instead of the actually attached_upload, which will be smaller in most cases because it can be an optimized image.
See #10794 for original context.
I did not mean to add invite to the BYPASS_TYPES for Email::Sender, it was supposed to be invite_password_instructions.
We had an issue where onebox thumbnail was too large and thus was optimized, and we are using the image URLs in post to redact and re-embed, based on the sha1 in the URL. Optimized image URLs have extra stuff on the end like _99x99 so we were not parsing out the sha1 correctly. Another issue I found was for posts that have giant images, the original was being used to embed in the email and thus would basically never get included because it is huge.
For example the URL 787b17ea61_2_690x335.jpeg was not parsed correctly; we would end up with 787b17ea6140f4f022eb7f1509a692f2873cfe35_2_690x335.jpeg as the sha1 which would not find the image to re-embed that was already attached to the email.
This fix will use the first optimized image of the detected upload when we are redacting and then re-embedding to make sure we are not sending giant things in email. Also, I detect if it is a onebox thumbnail or the site icon and force appropriate sizes and styles.
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.
See https://meta.discourse.org/t/email-address-change-confirmation-email-not-sent-but-every-other-notification-emails-are/165358
In short: with disable emails set to non-staff, email address change confirmation emails (those sent to the new address) are not sent for staff or admin members.
This was happening because we were looking up the staff user with the to_address of the email, but the to address was the new email address because we are sending a confirm email change email, and thus the user could not be found. We didn't need to do this anyway because we are passing the user into the Email::Sender class anyway.
This PR introduces a few important changes to secure media redaction in emails. First of all, two new site settings have been introduced:
* `secure_media_allow_embed_images_in_emails`: If enabled we will embed secure images in emails instead of redacting them.
* `secure_media_max_email_embed_image_size_kb`: The cap to the size of the secure image we will embed, defaulting to 1mb, so the email does not become too big. Max is 10mb. Works in tandem with `email_total_attachment_size_limit_kb`.
`Email::Sender` will now attach images to the email based on these settings. The sender will also call `inline_secure_images` in `Email::Styles` after secure media is redacted and attachments are added to replace redaction messages with attached images. I went with attachment and `cid` URLs because base64 image support is _still_ flaky in email clients.
All redaction of secure media is now handled in `Email::Styles` and calls out to `PrettyText.strip_secure_media` to do the actual stripping and replacing with placeholders. `app/mailers/group_smtp_mailer.rb` and `app/mailers/user_notifications.rb` no longer do any stripping because they are earlier in the pipeline than `Email::Styles`.
Finally the redaction notice has been restyled and includes a link to the media that the user can click, which will show it to them if they have the necessary permissions.
Two behaviors in the mail gem collide:
1. Attachments are added as extra parts at the top level,
2. When there are both text and html parts, the content type is set to
'multipart/alternative'.
Since attachments aren't alternative renderings, for emails that contain
attachments and both html and text parts, some coercing is necessary.
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
This feature is off by default and can can be configured with the `email_total_attachment_size_limit_kb` site setting.
Co-authored-by: Maja Komel <maja.komel@gmail.com>
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
- The test_email job is removed, because it was always being run synchronously (not in sidekiq)
- 34b29f62 added a bypass for critical emails, to match the spec. This removes the bypass, and removes the spec.
- This adapts the specs for 72ffabf6, so that they check for emails being sent
- This reimplements c2797921, allowing test emails to be sent even when emails are disabled
We can only be sure that an email is sent when we get a mailer in
`ActionMailer::Deliveries`. A couple of tests were actually incorrect
because it didn't flow through our email sender where there are more
conditions in determining whether an email is sent or not.
This change allows email-clients to show threaded views of mails as
expected. Apparently most algorithms expect the message ids of mails
in the Reference-header-field to be sorted such that they build a
traversal through the thread, so the oldest (original) message being
first, then its child, grandchild and so on until it arrives at the
message id that the "new" mail (that is to be sent) is the reply to.
MSGA [1]
+- Re: MSGA [1-1]
| +- Re: Re: MSGA [1-2-1]
| +- Re: Re: MSGA [1-2-2]
+- Re: MSGA [1-1]
If the stuff in brackets would be the message ID, the References-Header
field of a message that is a reply to [1-2-1] should look like:
References: 1, 1-1, 1-2-1
Discussion took place in:
https://meta.discourse.org/t/e-mail-threading-in-ml-mode-does-not-work-in-thunderbird
Main information taken from:
https://www.jwz.org/doc/threading.html
Martin Brennan
Bianca Nenciu
Gerhard Schlager
Daniel Waterworth
Krzysztof Kotlarek
Guo Xiang Tan
Sam Saffron
David Taylor
Rishabh
Régis Hanol
Arpit Jalan
Felix Wolfsteller
Guo Xiang Tan
Neil Lalonde
Robin Ward
