pop3 -> imap fails

[youx]

Hi,
whereas my installation of imp3/turba/mysql is working with a pop3 server, I
can't get into IMP when I try to access through imap (and I tried imap on
the console and it works with the username/password I tried to use in IMP)

I installed the UW imap and php is compiled with imap support in

in /horde/imp/config/servers.php I put :

$servers['imap']=array(
        'name' => 'IMAP Server',
        'server' => 'krakoukas',
        'protocol' => 'imap',
        'port' => 143,
        'folders' => 'mail/',
        'namespace' => '',
        'maildomain' => 'example.com',
        'smtphost' => 'smtp.example.com',
        'realm' => 'example.com',
        'preferred' => ''
);

where 'krakoukas' is the name of my server as I didn't know what else I
could put.
does someone know what I would need to change in order to get the imp/imap
working ?
And what is the aim of the smtphost as it is not present in the pop config ?

thanks
Loic