Q1:   For the software of IPMate W90, is there any way of changing the voice message in english for a voice message in other language?

A1:  Yes,the English voice messages are individual .WAV files, so you could change them to your own language version manually.
Here are the steps:
1. Record your own voice messages according to IPMateGWVoiceMessageScript.txt (Download).
2. Save your messages as 8KHz/16bit/Mono wave files with the filenames given in the script respectively.
3. In the folder where you have installed IPMateGW, replace the wave files with those you created in step 2(Default path is C:\Program Files\IPMateGW).