Seems like a number of people have been trying to figure out how to get PHP's mail() function to work in Windows.
I was trying to get Blat (command line email utility) to work but never got it to work, although this other guy said he did. If you can get this to work, let me know. Even still, you'd have to code something to call the thing... and then mail() would be unused (right?)... and you'd have to change any preexisting code.
Anyway, instead I found this really cool (and FREE) mail server for Win98/2000/ME/NT called PostCast Server. It's at www.postcastserver.com and, while running, will detect all your mail() calls from PHP and send the email on its merry way. Your server/pc is now the smtp server. And no need for any code changes in PHP.
That's all...
--out--