[Dovecot] Login with firstname.lastname instead of loginname

[Ralf Hildebrandt]

Some of our users use to login as
firstname.lastname
or
firstname.lastname at charite.de
instead of using the "correct"
"flastname" login name.

In order to get this behaviour a long-gone co-worker wrote an
authdaemon.pl, which speaks the courier-authdaemon protocol.

How can I emulate this behaviour with dovecot?

Basically, all I need is a usernamen mapping ala:

Ralf.Hildebrandt at charite.de	     rhilde
Ralf.Hildebrandt		     rhilde
for all my users -- I can generate this programatically using awk, but
how can I make dovecot use that?

-- 
Ralf Hildebrandt (i.A. des IT-Zentrums)         Ralf.Hildebrandt at charite.de
Charite - Universitätsmedizin Berlin            Tel.  +49 (0)30-450 570-155
Gemeinsame Einrichtung von FU- und HU-Berlin    Fax.  +49 (0)30-450 570-962
IT-Zentrum Standort CBF                    send no mail to plonk at charite.de