If you have issues sending mail via GlasPacLX and are using AT&T/SBC Global, you need to change the Port Number to 587 (Company > Settings > Email/Fax Configuration).
See image below:
Once you have made the port change, click test and send a test message. If it is successful, click save.
NOTE: All users must log off of the GlasPacLX server and log back in for their new settings to take affect.