It is running 4.41c now.

I don’t remember ever upgrading the voicemail file on the MP10. I probably have the same one since 4.07 Is this important?

Was running on 4.30 A-K for a fair while when I first tried to get it going.

I do have the option to send to a private IP as we have a VPN tunnel to the mail server which our PC's all use. I couldn’t get it to work on private either so that’s why I started sending to the public IP.