Users getting 4 emails on merge request creation

Hi everyone!

Since a recent upgrade to 12.10.11, single users are reporting that they will get four individual emails on the creation of a merge request. I have checked those emails, they are only a few seconds apart and, other than the “X-Gitlab-Reply-Key” header they seem to be identical.

The user has configured watches for groups and projects, but still, only one email should be generated (instead of four).

Describe your question in as much detail as possible:

  • What are you seeing, and how does it differ from what you expect to see?
    The user gets four emails when a merge request in a watched project is created.
    The user should get this email only once.
  • Consider including screenshots, error messages, and/or other helpful visuals
    Don’t have any (or rather: wouldn’t know what to send).
  • What version are you on (Hint: /help) ? and are you using self-managed or gitlab.com?
  • 12.10.11 (171498bd025) community edition, self managed
  • What troubleshooting steps have you already taken? Can you link to any docs or other resources so we know where you have been?
    Checked the (raw) emails and found the “X-Gitlab-Reply-Key” header missing.
    Found this link about the very same topic, but that yields a 404 only (and is not in the Internet Archive): https://gitlab.com/gitlab-com/support-forum/-/issues/4920

Hey @sbreit!
Have you managed to solve your issue? If yes, can I ask you how? Because we are experiencing the same behaviour since a couple of weeks.
Thanks!