Il giovedì 10 giugno 2021, 13:12:09 CEST, Josef 'Jeff' Sipek <jeff.sipek@open-xchange.com> ha scritto:

If I'm understanding you correctly, it looks like you have a different

mail_location set on the two servers. In one case it appears to have a
mail/<domain>/<user> sort of format, and on the other... well, I have no
idea but it looks like it is only mail/ or something similarly incorrect :)

Exactly, the different structure seems to be due to a different configuration of the mail servers.

In the end, having no experience with Dovecot and its migration utilities, I found it much easier to use Imapsync.