use Mail::Message;
my $fromline = <STDIN>;
my $msg = Mail::Message->read(\*STDIN);

if($msg->isMultipart) {
  for($msg->body->parts) {
    open(my $tofile,">/tmp/filename")
      or die "Error opening tmpfile: $!";

    $_->print($tofile);

    close $tofile;

    # print
  }
}