<p>The Github notification mails I receive for this pull request don't have a root message, only those two header fields. However, all mails share the same title (e.g.<code> [openstreetmap/openstreetmap-website] Add In-Reply-To, References headers to email (#2462)</code>), and that may be the reason why threading works with Github notifications in gmail. Current osm emails don't include anything specific except for the user name that sent the email maybe.</p>
<p>I'm a bit reluctant to push this change as it is now to production, given that probably a fair amount of people uses gmail inbox. Can we somehow refine this on master for a bit without pushing to production, or have it inactive in production?</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/openstreetmap/openstreetmap-website/pull/2462?email_source=notifications&email_token=AAK2OLLFO7BJA6G52EB26MDQ3MHZXA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEH37K5A#issuecomment-569898356">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AAK2OLMK34JEP4NNYZUAIDDQ3MHZXANCNFSM4JZ3T73Q">unsubscribe</a>.<img src="https://github.com/notifications/beacon/AAK2OLNSYQCMVJSJE5JRLBTQ3MHZXA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEH37K5A.gif" height="1" width="1" alt="" /></p>
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