digging the mail archive and the forum i realized that many of us prefer squirrelmail as the webmail option to provide easy access to our customers to their mails using their browsers. i also realized that at this moment ISPConfig developers are way too busy to develop support to squirrelmail in a form so that users don't need to use their 'ugly' web[WEBID]-user format username but email@example.com
giving it some time i thought of an idea of creating a pam module which translates firstname.lastname@example.org
according to postfix's virtualuser.db database to real username's with which the client can be authenticated.
please (ISPConfig developers) let me know if there's need for such a feature. i'd not like to work in parallel with you guys.
ps: the reason i'm not thinking of writing a squirrelmail auth plugin because in the pam module case other services can make use of this method, such as ftp or imap/pop daemons.