if ($opt{'c'}) {
   open MAILLOG_R, "<$MAILLOG"
     or die("Unable to open mail log: $!\n");
 } else {
   tie *MAILLOG_R, 'File::Tail', (name => $MAILLOG, tail => -1);
 }

 while(my $line = <MAILLOG_R>) {
  ...blah...
 }