Merlin Messaging won't get it either. There is no option for Centrex Transfer from a selector code in the Auto Attendant, like there is in Partner Messaging. I've been caught there before.

The reason is that Single Line extensions (which is what the voice mail ports are) cannot do a flash to the outside line.

However, if your Legend is R6 or higher, there is "Centrex Transfer via Remote Call Forwarding" - You forward an extension to an outside number, but instead of 9 for an outside line, you program it with * and pause, then the outside number.

You would create "phantom" extensions using adjunct ports, give them AND the voice mail ports permission for RCF and Trunk to Trunk transfer, give the adjuncts authorization codes so that you can forward them, and finally you can direct your selector codes to the new, forwarded, extensions.