consider dovecot upgrade

[Jim McFarland]

Dear Sirs:
As you probably already know, Dovecot 1.1.xxx is crippled. It can't handle  
the "dot" in a full url name when this format is used in a directory name  
on the server. Postfix will deliver mail to a Maildir in to a directory  
named like "mysite.org" but Dovecot cannot handle this format.
example= "/var/vmail/jmcfarland.org/jim/Maildir" cannot be seen by Dovecot  
1.1.xxx but it can see "/var/vmail/jim/Maildir".

According to the Dovecot author, this problem has been resolved in Dovecot  
1.2
For this reason I would encourage you to make DoveCot 1.2.xx or better the  
Ubuntu distribution flavor.