Email does not send the task to zammad but receives it

[spats]

There isn’t enough information in your post to really know what is wrong yet, so here are some rapid fire suggestions.

I would recommend reviewing this documentation:

Email — Zammad documentation

I would also recommend upgrading your Zammad instance to the latest available release. Zammad 4.0 is over a year out of date and you’re missing many security updates and improvements.

News, Updates, Releases | Zammad

Updating Zammad — Zammad documentation

Lastly if you’re using Microsoft Office 365 email, you may want to review this thread, as you may be experiencing the same issue

Problem with Office365