If you transfer a voicemail to a mailbox and they don’t arrive, then that person might not have synchronicity between their Extension number and their voicemail box number. I had a case where this happened and the mailbox was in use by another extension (which didn’t exist) that was also setup in an active CCR Tree. This made it impossible to reassign the mailbox to the correct extension. Here are the steps I took in resolving:
5/29/07 – Our system (MICS 4.1.1 with NVM 8).
1) Open CCR, find entry in the Tree that used the extension that wouldn’t setup in VM.
2) Disable that CCR tree
3) Point the offending entry to another extension.
4) Save the Tree
5) Keeping that tree disabled, reboot the whole phone system. After it comes up, you should be able to setup a mailbox with the extension you want.
**Don’t forget to repoint the Ext that you changed in the CCR tree and reenable the Tree you disabled**
In this case, the enabled CCR Tree was using a voicemail extension that wasn’t setup. You may also be able to skip the part about pointing the ext to another ext and simply disable the tree and go on.
Note: Due to how dated this system is (circa 2001), the issue may have been fixed by a Nortel software update.