** This all assumes that you are running 8.2 or lower**
I'm not exactly sure about which ports are needed, but let me see if I can help get you started. If you want to receive/send traffic to the outside world you will need to configure static/access-lists to allow that traffic.
Here is a document on the list of the ports according to Microsoft.
http://technet.microsoft.com/en-us/library/bb331973.aspx
Say my server is on the inside with an IP address of 192.168.1.5 and I want to translate it to my open public IP of 99.9.9.9. To do the static statement for pop3 it would look something like this
static (inside,outside) tcp 99.9.9.9 110 192.168.1.5 110 netmask 255.255.255.255
**note** If you want to use the outside IP address of the ASA to translate your server to you can use the interface keyword
static (inside,outside) tcp interface 110 192.168.1.5 110 netmask 255.255.255.255
For the access-list I would use something like:
access-list outside_access_in permit tcp any host 99.9.9.9 eq 110
Then make sure that you have an access-group applied to the outside
access-group outside_access_in in interface outside
Hopefully this helps