Somehow I'm not clear about receiving emails. I want to read all mails from our server into Odoo, so that they appear in the mail history with the employees in the inbox and with the customers.

I did that:

Odoo 12 CE installed on Windows Server 2016 (Vserver), with modules Discuss, Calendar & Contacts (so very little)
created three users: admin@mydomain.de, test@mydomain.de and employee@mydomain.de
each created the alias: admin, test, coworker, with Model = User, Record thread ID = respective user number. Notification Management = Handle in Odoo, Alias ​​Contact Security = Everyone

In order to be able to receive all Mails of 1 & 1, I had to find a workaround: With 1 & 1 "*@mydomain.de" is the catchall address. The * can not be registered with Odoo. Therefore, I have set up a redirect from *@mydomain.de to catchall@mydomain.de (own mailbox). In the webmailer I also see the mails that arrive there.

In Odoo I have created the incoming mail server "catchall@mydomain.de", which is also confirmed.

If I now retrieve mail (Incoming mail server - fetch now), the mails appear in the 1 & 1 webmailer as read and the internal mail server is the correct time on the last Fetch Date, so it was retrieved. Under Email count, however, "no records" appears and I can not find any mails in Odoo. Not under technical-messages, not under technical-emails, not in the inbox of the users and also not at the customer.

In odoo.log nothing new appears at the time of the mail retrieval.

What can I do?