[Dovecot] migrate from cyrus with virtual domains

[Andrey Kolbasenko]

Hi All!

I have worked cyrus+web-cyradm+mysql+virtualdomains configuration, and want 
migrate from cyrus to dovecot by some reason. But i don't know how i can 
switch my users to dovecot, wich have dotted logins in their mail clients 
configuration: 

user1.domain1.org
user2.domain1.org
user1.domain2.org
...
 
I want preserve this dotted authentication theme, but don't know how do it 
with dovecot.

---
Wbr,
Andrey Kolbasenko