[Dovecot] Problem with different case logins

[Roberto Suarez Soto]

Hi,

	we have a system (Debian sarge) that uses LDAP for user
authentication, via pam.  We also have virtual users by using a static
userdb [1], using the directory structure /var/lib/dovecot/postoffice/%u
(i.e., a directory under /var/lib/dovecot/postoffice with the name of the
user). The directory /var/lib/dovecot/postoffice belongs to
postoffice:mail. IMAP folders, indexes and stuff go here; normal mail goes
into /var/mail/%u. We are using dovecot 1.0alpha3 (upgrading to alpha4
soon).

	Today we've found a grave problem. Let's suppose you have the login
"mylogin.domain.com". If you instead use the login "MYLOGIN.domain.com",
the authentication works anyway (which is Ok), but dovecot creates a new
directory under /var/lib/dovecot/postoffice with the different case, i.e.,
/var/lib/dovecot/postoffice/MYLOGIN.domain.com (which is not Ok).
Afterwards, you can only access this new folder if you use the login with
the caps. A new file (we're using mbox) under /var/mail/ with the new name
is also created, though I don't understand yet how. We're using Postfix as
MTA, and it always delivers to the lower case name.

	I hope you can understand the problem. If an user logs with a name
with just one letter changed from lower case to upper case, all his/her
folders and mail will be seemingly gone.

	Is this a bug or a feature? If the latter, is it possible to change
this behaviour, or at least work around it?

	Thanks in advance.

-- 
	Roberto Suarez Soto				Allenta Consulting
	robe at allenta.com				   www.allenta.com