$SIG{PIPE} = sub { die "Your pipe handler here! $!"; };

 $prog = "/var/qmail/bin/qmail-remote";
 $msg = "this is the email message";
 open (OUT, "|$prog") or die "Couldn't open Qmail: $!; stopped";
 print OUT $msg;
 close(OUT) or die "Couldn't close Qmail: $! $?; stopped";

 my $return_code = $? >> 8;
 print STDOUT "My return code was $return_code.\n";