In testing my call handers I have found that if you dial an extenstion during the greeting it only transfer to that extension when that extension has mailbox configured on the system. If the extension in call manager does not have a voice mailbox configured in Unity Connection then the transfer does not work.
When you dial our main number, the greeting tells the caller that if they know there parties extension they can dial it any time. This only works for extensions that have mailboxes.
Do I need to configure mailbox's for every phone even if they are not getting voice mail? Phones such as breakroom or conference room?
If you're running CUC 7 you just need this:
Allow Transfers to Numbers Not Associated with Users or Call Handlers—Check this check box to allow callers to transfer to extensions that are not assigned to other users or call handlers. Connection attempts a release transfer as long as the number entered by the caller is allowed by the Default System Transfer restriction table.
If this helps, please rate