my $sendmail = '[path_to_sendmail]/sendmail.exe';

open my $sendmailFH, "|$sendmail" or die "Cannot open $sendmail: $!";
print $sendmailFH "Subject: $subject\n";
print $sendmailFH "From: $from\n";
print $sendmailFH "To: $to\n";
print $sendmailFH "Content-type: text/plain\n\n";
print $sendmailFH $body;
print $sendmailFH "\n.\n";

close($sendmailFH);