Have them look at the label on the front top tab. It will say "Merlin Messging" on the next line there will be a model# (617A49, 617B49, 617C49, 617D49, etc.) Each model# corresponds to a different version. If the module is a 617C49 or higher (R2.5) - it may have been upgraded to Messaging R4.0. The only way they could tell that was if they could dial in to the admin mailbox and press 7 - to hear the release announcement - but obviously they cannot access the admin mailbox. But, let's at least start with the model#.
Tom Daugirdas,
President
STCG, Inc.
stcg.com