[imp] Cannot connect with IMP to IMAP, login failed

[Wim]

Hi,

I am trying to connect Horde/IMP to my IMAP server but I always get 'Login Failed'. I am sure that my
credentials are correct as these are working fine with a Mail Client (Mozilla). I can connect also to my
IMAP Server with Squirrelmail (standards-based webmail package written in PHP4). Horde is running on the
same server as my IMAP Server.
This is my config in servers.php

$servers['imap'] = array(
    'name' => 'IMAP Server',
    'server' => 'localhost',
    'hordeauth' => false,
    'protocol' => 'imap/notls',
    'port' => 143,
    'folders' => 'INBOX.',
    'maildomain' => 'example.com',
    'smtphost' => 'localhost',
    'smtpport' => 25,
    'dotfiles' => false,
    'hierarchies' => array()
);

This is what I get in the horde.log
HORDE [error] [imp] FAILED LOGIN x.x.x.x to localhost:143[imap/notls] as 'user' [on line 247 of
/webroot/horde/imp/lib/Auth/imp.php"]
HORDE [info] [imp] x.x.x.x failed [on line 31 of "/webroot/horde/imp/login.php"]

Anyone an idea what the problem can be.

Many thanks,