I knew there already was such a module, but I looked (twice) through CPAN and didn't find it, so I rewrote it (and it wasn't hard to do).

Thanks for finding it for me! Now I'll simply turn my module into some glue and use the other module :-)

I am new to all of this but need similar help. I found the Mail::DeliveryStatus::BounceParser but do not understand how I might have it parse my inbox to provide the email and reason the email rejected.

The synopsis of Mail::DeliveryStatus::BounceParser tells me that it wants each mail fed to it separately. As you have a file in mbox format containing several mails, you'll have to split up that file first, and then pass the single mails to Mail::DeliveryStatus::BounceParser like this, according to the synopsis:

use strict;
use Mail::DeliveryStatus::BounceParser;

my $mail; # current mail

while (<>) {
  if (/^From:/ && $mail) {
    my $bounce = eval { Mail::DeliveryStatus::BounceParser->new( $mail
+ ) };
    if ($@) { 
      warn "Got error from M::DS::BP: $@ while parsing input" 
    } else {
      my       @addresses = $bounce->addresses;       
      my         @reports = $bounce->reports;         
      my $orig_message_id = $bounce->orig_message_id;
      my $orig_message    = $bounce->orig_message;
      print "Got bounce for $orig_message_id (@reports)";
    };
    $mail = "";
  };
  $mail .= $_;
}
[download]

That's all there is to it. The code is untested but should work like that.