What type of voicemail system? How are you "getting" to this mailbox?
The application matters, so i will expand....
If you have a "phantom" mailbox, we will call this mailbox 543, you creat the mailbox. Then you go into the Pub Lib portion of the Tadiran and create a library....we will call this 6543 (default public libraries are usually 6000-6999.
In the last portion of this library, you insert the APDL or target of the voicemail (we will call this 5555.
On a DID call, (offset filters) you point from 543 to 543 to 6543. The inbound call is "sent' to mailbox 543 (as i am taking for granted you have a valid voicemail already set up and they are 3 digit extensions and you have done the remapping already.) To transfer a call directky to the "phantom mailbox, revenge of the sith", you do transfer 6543.
On a regular line that would "ring" to the "phantom mailbox", you would go into trk and set the trk to d.i.l. the library (65430.
Hope this helps.
Metballnut