distuguish between different domains

[Andreas Meyer]

Hello!

I asked myself wether it is possible to distinguish between
different doamins in dovecot so that a user only sees his
mailbox when he is connecting with user1 at aaa.de specifying
the server with mail.aaa.de for example.

So the server does not handout the mailbox for user1 at bbb.de
when the client connects to mail.aaa.de as user1 at bbb.de

I have this problem with roundcube. Dovecot is responisble
for two domains. With roundcube I can login as user1 at aaa.de
altough the client is configured like so:
$config['smtp_server'] = 'tls://mail.bbb.de';
and I am landing in the mailbox of user1 at aaa.de

Is there a way to striktly differentiate between doamins?
Both domains have their own IP-addresses.

Regards

  Andreas