As others have commented, you may find the CPAN modules make this easier to implement (I know I have).

Currently, I'm using MIME::Lite, which let's you do something like this:

my $sender = 'yourname@example.com';
my $msg = MIME::Lite->new(
        Type       => 'TEXT',
        From       => $sender, 
        To         => 'theirname@example.com',
        Subject    => 'Simple Greeting'
        ReplyTo    => $sender,
        ErrorsTo   => $sender,
        Data       => 'Greetings, Lifeform!'
     );

$msg->send_by_smtp( 'localhost' )
   or die "Unable to send message; reason $!\n";
[download]

Note: the above is off the top of my head, so there may be typos or other silly mistakes. If so, sorry.

The interesting bit, I think, in the above is the ErrorsTo line. That seems to work, provided you take care to send it to an appropriate address. For example, I have a special mailbox devoted to those errors.

MIME::Lite also offers several alternatives for sending. For details, check the docs.

Hope this helps...

--f