Massive mail delay

  • Used Zammad version: 3.6.x
  • Used Zammad installation type: install from package
  • Operating system: ubuntu 20.04 LTS on AWS EC2
  • Browser + version: Safari current version

Expected behavior:

  • sending mail immediately

Actual behavior:

  • delay of several hours, sometimes more than a day

Steps to reproduce the behavior:

  • From one second to another we have problems in sending and receiving mails. First the mail configuration was not possible (WRONG LOGIN) and later it was possible to create a new configuration and we receive tickets over the channel. But if we send an answer or forward a mail we have a massive delay in receiving the mail (hours and somedays more than one day!).

Things we did: Restart Zammad, restart server, tried other mail account (not Office365), configure and use local sendmail, rebuild elastic search index, stop elasticsearch service

Will be happy about any hints!

We solved that by

  • reconfigure the notification mail settings and
  • reindex the elasticsearch