Hey! It's me again. I solved the problem. Well, not exactly... I have to say that I don't know which the problem was, I restarted the howto, recompiled postfix, etc.. and now it works... But I have another problem:
I tried to install squirrelmail with the howto http://www.howtoforge.com/virtual-us...-5.3-x86_64-p5
and when I type the username and password and press login in Squirrelmail an error appears
ERROR: Connection dropped by IMAP server.
In the maillog I see:
Feb 2 20:55:29 server imapd: Connection, ip=[::ffff:127.0.0.1]
Feb 2 20:55:29 server imapd: LOGIN FAILED, firstname.lastname@example.org, ip=[::ffff:127.0.0.1]
Feb 2 20:55:29 server imapd: authentication error: Input/output error
I've installed Thunderbird and fails too. Any suggestion?