Intermittent Missing Emails in Zammad System


  • Used Zammad version: 6.2
  • Used Zammad installation type: Docker
  • Operating system: CentOS
  • Browser + version: Chrome, latest version as of submission date

Expected behavior:

  • All incoming emails should be consistently received and visible in the Zammad system.

Actual behavior:

  • Randomly and without any apparent pattern, some emails that are visible in the email client are not received in the Zammad system. This issue occurs sporadically with no clear triggers, affecting approximately 1 in 10,000 emails.

Steps to reproduce the behavior:

  • The issue is intermittent and does not have reproducible steps. Emails simply fail to appear in Zammad without a discernible reason.

Additional Information:

  • Triggers, Schedulers, and Filters have been checked and do not seem to be causing the issue.
  • Server resources appear to be underutilized, suggesting that the server’s performance is not the bottleneck.

Attachments: Please refer to the attached screenshots showing an email that is visible in the email client but not found in Zammad’s system.

Hi @Nuri. With the given information it’s not possible to help you here, I’m sorry.

Hello, is there anything that I could add that would help?

Hi @Nuri. Your complete mail setup might be interesting I guess. Not sure though.

Hello, what exactly from the Mail setup should I send?

Hi @Nuri. How are the mails fetched?

Over IMAP, with ssl no ssl verification on port 993

Simple guess: The mail is flagged as read, this is why it’s not available in Zammad.

I will take a look at this. Thank you!