smiffypr: Yes, I think getting the messages by email is very useful, but, the difference between land-line and voip calls to the 2talk voice-mail were not as distinctively different as those recorded by Telstra voice-mail. I don't know if that is because the wav files are very low bit rate, or some other reason.  It could even be that the player I'm using to play the files is hiding the differences.

low-bit rate encoding. I use an account here, and there is noise over the phone link, and in the recording (it's all compressed).