That would be an Avaya Partner Messaging.
There are 2 avenues you can take to reset the Administrator's password:
One option is to contact Avaya directly. They can reset it, but they charge quite a bit for the service.
The other option would be to contact an Authorized Avaya Business Partner in your area. They can reset it for less than what Avaya charges, and also provide you with a good contact should a major problem arise with the phone system.
For legal and other reasons, the password reset procedure cannot be posted on open forums like Tek-Tips.
If it ain't broke, I haven't fixed it yet.