I'm attempting to setup vpopmail on my CentOS server (Media Temple). Everything is working like a charm, with the exception that I cannot login to the server from any pop3 client. Upon trying to login I get the following error:

 Sending of password did not succeed. Mail server mail.(mydomain).com responded: Login failed.

I'm running qmail (of course) with xinetd (not tcpserver). I've placed a file called pop3 into the folder /etc/xinetd.d with the content:

service pop3
{
    disable              = no
    socket_type          = stream
    protocol             = tcp
    wait                 = no
    user                 = root
    server               = /var/qmail/bin/qmail-popup
    server_args          = mail.(mydomain).com /home/vpopmail/bin/vchkpw /var/qmail/bin/qmail-pop3d Maildir
    log_type             = FILE /var/log/xinetd.log
    log_on_success       = HOST
    log_on_failure       = HOST RECORD
}

Can anybody offer any guidance here? I've been unsuccessfully trying to make this happen for over a week.