FYI for those using RT
I have setup Request Tracker (bestpractical.com) on another server. Configuration & Testing has worked very well. This server is not open to the internet. Then, I needed someway for people to send tickets via email. There was no problem with people sending while logged onto the Zimbra server (btw, it is a NE 5.0.14 on a dedicated server) since I have the server / ip in the /etc/hosts file. But, I have employees that are on a separate network & mail server that would not be able to send to RT.
I tried creating an alias, but it would not allow to create it for a third level domain. After messing around with my original department distribution list, it finally hit me that an alias was not necessary. Just create another DL with the appropriate email address. Reconfigure the RT reply and comment address and then it's done!