Topic: IMP webmail

[EdelingF]

When I use webmail by using the URL http://www.mydomain.nl/webmail I can login, but if I use http://webmail.mydomain.nl I get the login-screen, but can't login.
I get the error: http://webmail.mydomain.nl/horde/imp/login.php?1=1&imapuser=horde&server=imap&reason=failed


Does anyone know whats wrong?

(I've asked this question once before, but didn't get an answer)