OK, no answers here, just a post to let everyone know that you are not alone, same platform and exact same symptoms. Win 2000 Pro, SP4.
I have tried this software on Win 2000 Pro, Win XP Pro and Win Media Center Edition, I get tapisrv.dll application crashes on XP and MCE. Win 2000 is the only one that it has been stable on but as you have noticed, it wont send mail.