[RCU] logging in from different domains

Hello!

I have asked a similar question in the past but got no satisfying answer.

With roundcube I connect to dovecot on port 143. The thing is I can connect to the IMAP-server with user@aaa.de to user@bbb.de. Both domains exist on the IMAP-server.

Even if I specify $config['default_host'] = 'tls://mail.bbb.de'; I can connect with user@aaa.de and get into the mailbox of user@aaa.de

I find this somewhat crazy and annoying. I was hoping that when I configure auth_realms = aaa.de bbb.de in docecots config, the differences would be honoured but it isn't like this.

What steps need to be taken that such a cracy behaviour does not happen? Or is it just not possible to distiguish between different domains?

Regards

Andreas