- 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
- sending mail immediately
- delay of several hours, sometimes more than a day
- 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!