[Dovecot] Using account alias as login

[Javier Amor García]

Hello,
 I use dovecot with a LDAP backend for user account and aliases. The aliases
are objects of the class couriermailalias.
 Some users would like to use the alias address as POP/IMAP login instead of
the 'true' account.
Is this possible?.
I am using dovecot version 1.0,10, from ubuntu hardy packages.

Thanks for any answer,
  Javier