Re: Some correspondents have kolab_user@kolab_server instead of From address in their replies

Valentin Laskov <[email protected]> Tue, 7 Dec 2021 17:27:13 +0200
Newsgroups gmane.comp.kde.devel.kroupware
Message-ID <e101a47b-43bb-b3c9-ad2d-72a73d9a829f__29190.6807733298$1638890896$gmane$org@festa.bg>
Also
for your primary domain you have alias domains - have a look at 
https://docs.kolab.org/architecture-and-design/ldap.html#multi-domain-deployments

and again - postfix config