ASA5510 IMAP Port Forwarding

What lines do I need to add to the ASA5510 to enable port forwarding to an internal IMAP server.

Here is what I have:

access-list outside_access_in extended permit tcp any host

206.111.111.111 eq imap4 static (inside,outside) tcp 206.111.111.111 imap4 192.168.1.8 imap4 netmask 255.255.255.255 access-group outside_access_in in interface outside

This is what I have on a PIX501 (6.3) and it works like a charm, but not with the 5510. I appreciate your time and any suggestions you may have, Dave.