Your syntax looks fine to me:
One thing I did spot is this:
$mailprog is looking for the system path to sendmail. It's usually /usr/sbin/sendmail but it appears that you are on a windows server. Check with your host and see if they have a sendmail alternative that you can use instead.
Check a couple of things: 1) Make sure you are using the correct copy of formail.pl. Use an absolute path on your form instead of a relative path. 2) Make sure that you actually uploaded the file in ASCII and not binary. I can't remember if makes much of a difference on Windows though.
Other than that, I'm stumped. You're not missing a semicolon in the code you posted, that's for sure.
~Charlie