use MIME::Parser;
use Mail::Address;

my $parser = new MIME::Parser;
my $MIME_entity;

eval {
  $MIME_entity = $parser->parse(\*STDIN);
}

if ($@) {
  print "Trouble parsing mail:\n";
  print $parser->results->msgs();

} else {
  my $header = $MIME_entity->head();

  my $subject = $header->get('Subject'); # Assumes one subject header
  print "No Subject header found!\n" unless defined ($subject);
  
  my $from = $header->get('From'); # Assumes one From header
  print "No From header found!\n" unless defined ($from);
  
  my @from_addresses = Mail::Address->parse($from);
  my $address;
  if (@from_addresses) {
    # Assumes 1st address is the only one we care about
    $address = $from_addresses[0]->address();
  } else {
    print "No address found in from line!\n";
  }

  print "Subject is $subject\nMail is from $address\n";

  # See the MIME::Entity manpage for clues on how to muck about with
  # the body of the email here

}

$parser->filer->purge();