Transfer directly to voicemail

In case you do not want to upgrade to CME 4.3

To transfer a call directly to voicemail, you have to be able to call directly into a voicemail box. To do that, you have to make the call look like it was forwarded to voicemail instead of being a direct call. The normal way to do this in CME is to create an ephone-dn and forward it to voicemail. It is common to match the phones' extensions with a leading digit, such as *. The number on this ephone-dn will be something like *.... (for * and any 4 digits). You could be more specific with the extensions, like *21.. or *[2-5]... . Configure call-forward all on this ephone-dn to the voicemail pilot number. Then, on the dial-peer pointing to the voicemail pilot, you need to translate the redirecting number to the mailbox number. In this example, that means removing the leading *.

The config looks something like this:
voice translation-rule 4
rule 1 /^\*/ //
!
voice translation-profile vmbox
translate redirect-called 4
!
dial-peer voice 1000 voip ! existing cue dial-peer
destination-pattern 1501 ! vm pilot number
translation-profile outgoing vmbox
!
ephone-dn 51
number *....
call-forward all 1501

With this config you can call or transfer, for example, to *2501 to get to
voicemail box 2501.
If you are using Unity (or Unity Connection) and not CUE, you will have
ephone-dn's that are associated with Unity instead of an outbound voip dial-peer.
The translation-profile should be applied to these ephone-dn's.

In the new version of the software, there is now a TrnsfrVM softkey. Update your IOS to the latest version, and you should be able to configure it. Check out the CME 4.3 documentation. may be safest to wait for the newest UC520 support package, which will include all the necessary software. should be out in a month or two.