HI Is it possible to disable internal messaging?
I installed a TDE100 in a school. They have a Bogen intercom system with single line telephones in the class rooms. The reception is getting internal messaging as well as voice mail messages. They were wondering if it is possible to turn off internal messaging? Thanks for your help.

I believe you could go in to System Numbering,
B/NA DND Feature and remove the 4.

Yea I always take out 4 in the feature numbering plan for every install. That should do it for you with slt sets.