1674796 - Phabricator emails: Use threading headers

Status: RESOLVED FIXED

(Conduit :: Phabricator, enhancement, P3)

Description

[Mitchell Hentges [:mhentges] 🦀]

See this report on Matrix.
For most email clients (except for GMail), there's a "thread" header that is respected for grouping emails. This makes threads resilient to subject changes.
We should use this header.

Comment 1

[Magnus Melin [:mkmelin]]

Yes, the standard header is "References"

Comment 2

[Rob Lemley [:rjl]]

The "legacy" notifications had the References header and threading worked as expected. The new "Mozilla Notifications" do not have this header, so threading does not work in Thunderbird.

Comment 3

[Mitchell Hentges [:mhentges] 🦀]

For those whose clients don't thread by email subject, you can revert back to the builtin Phabricator Emails until this is resolved.

Comment 4

[Steve Fink [:sfink] [:s:]]

See also bug 1535688 (where it was triaged as conduit-upstream, but it sounds like there may not be an upstream anymore?). Also note that there is a setting to prevent Phabricator from changing subject lines, which has been helpful for me in getting decent threading with both the new and old email formats.

Comment 5

[Mitchell Hentges [:mhentges] 🦀]

where it was triaged as conduit-upstream, but it sounds like there may not be an upstream anymore?

Yeah, there's two different email implementations: the builtin/upstream Phabricator one, and the Mozilla one that because the new default yesterday (which this bug is in reference to, I believe).

Also note that there is a setting to prevent Phabricator from changing subject lines

The new Phabricator emails don't change subject lines by default (unless the revision title changes). It doesn't currently integrate with that setting.
However, there has been an issue floating around about emails with the same subject not being threaded in GMail, which is worth investigating, but is a bit orthogonal to this ticket.

Comment 6

[Mitchell Hentges [:mhentges] 🦀]

There's more action in this ticket than I anticipated, I'll take a look.

Comment 7

[Mitchell Hentges [:mhentges] 🦀]

Attachment: GitHub Pull Request

Comment 8

[Mitchell Hentges [:mhentges] 🦀]

This has landed, but I'll leave another comment when it's deployed.

Comment 9

[Mitchell Hentges [:mhentges] 🦀]

This has been deployed.