Thanks Till for the reply. Well, that is sad. Given that I am using Dovecot for POP, is there any other way I can 'point' the password file to something that allows @ usernames?
Or, can I modify the '/etc/passwd' file somehow?
Is there anything at all I can do about this - I don't care if it is a very long solution (change things by hand), but the thought of having to call all my customers is very daunting.
How come I can use roundcube mail with firstname.lastname@example.org