Kerberos 5 realms & cyrus mailboxes

[Dmitry P. Schegolev]

      Hello!

I have a number of questions about kerberos support in cyrus imap 
server. I tried to find answers in cyrus documentation but found nothing.

1) How does the kerberos principals maps into mailbox names?

Can I do the following  with cyrus:
Man with kerberos realm dmitry at EXAMLPE.COM  has access permissions  to  
certain  number  of  mailboxes, for example:
support at example.com,  dmitry at example.com,  mailbox at example.com?

If it  possible, how I can administer, to what mailboxes realms has  
access rights?

2) Can cyrus serve several number of mail domains?
I need virtual mail hosting on one server for a number of mail domains, 
for example,
@dgap.mipt.ru, @fopf.mipt.ru, @rt.mipt.ru...
And mailboxes in cyrus must be completely different, i. e. 
dmitry at dgap.mipt.ru, dmitry at fopf.mipt.ru, dmitry at rt.mipt.ru --- are 
different mailboxes.
If it can, how I ought to configure cyrus to get virtual hosting?

3) How does "by default" kerberos principals maps into mailbox names?
For example, for what mailbox I get access with principal 
dmitry/People at EXAMPLE.COM?

Thanks in advance,
Dmitry.