We have a customer who wants incoming calls that have been transferred from the Receptionist to a hunt group, to go to a group mailbox if unanswered. Voicemail is installed and works fine on individual extensions but I'm struggling to get it to answer group calls. Any help would be much appreciated.

I'm just taking a guess here, and I'm sure someone more experienced will also chime in, but I'm thinking the easiest way to do what you're describing would be to configure the VPS for "supervised transfer".

I use ring groups and overflow to vm. Have UCD overflow to to VM pilot number and have a mailbox for the UCD group number.
UCD - 191 Over Flow Number - 165 Time table - 1
For phone system to handle UCD from AA xfer would be unsupervised.

Have somebody who can do it login remotely to the PC conected to your system to configure it for you.