my $oldmail = "mailfile.eml";

my $parser = new MIME::Parser;
my $entity = new MIME::Entity;

$entity =  $parser->parse_open($oldmail);
$newmail = create_mail($entity);
open(NEWMAIL, ">newmail.eml");
print NEWMAIL, $newmail->as_string;



sub create_mail {
    my $mail = shift;
    my $encodetype = $mail->head->mime_encoding;
    
    if ($encodetype eq "base64") {
        my $body = $mail->bodyhandle;
        my $fname = $mail->head->recommended_filename;

        open(BODY, ">$fname") or die "Cant...";
        print BODY $body->as_string;
        close(BODY);

        my $contype = $mail->head->get("Content-Type");
        my $contranencode = $mail->head->get("Content-Transfer-Encoding");
        my $condispo = $mail->head->get("Content-Disposition");

       
        my $attachment = new MIME::Entity->build(
                                       Path => $fname,
                                       Type => $contype,
                                       Encoding => "base64",
                                       Filename => $fname,
                                       Disposition => $condispo);
        return $attachment;
   } elsif ($mail->parts > 0) {
       my $ent = new MIME::Entity;
       my $head = "mailhead.hdr";
       open(HEAD, ">$head") or return printerror();
       $mail->head->print(\*HEAD);
       close(HEAD);
 
       $ent->head(MIME::Head->from_file($head));
       foreach my $part ($mail->parts) {
           my $subent = compress_mail($part);
           $ent->add_part($subent);
       }

       unlink $head;
       return $ent;
   }
   return $mail;
}