Hi Manoj,
GDM in Unity Express can be configured in the GUI or the CLI.
Guides can be found here.
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/prod_maintenance_guides_list.html
It involves creating a group of users, and then creating a mailbox for that group. To retrieve messgaes from the GDM, each user must have their own Personal Mailbox. The can access this by dialling the VM Pilot number and entering their PIN - GDM is Option 9. If you have an NM-CUE module, GDM messages can be retrieved from VoiceView Express (again instructions can be found in the CLI/GUI Administrators Guide).
If this post helps, please rate!
Regards,
Dave
