For making MailWatch work with Debian 11 and PHP 8, I had Fixed few code-file to avoid error :
PHP Fatal error: Array and string offset access syntax.
Sharing below changes for users using with PHP8., Hopeful to update in new version or users trying to use MailWatch with PHP8.
-Deepen.
Please change this 100% working
$c1 = $text[$i];
if ($c1 >= "\xc0") { //Should be converted to UTF8, if it's not UTF8 already
$c2 = $i+1 >= $max? "\x00" : $text[$i+1];
$c3 = $i+2 >= $max? "\x00" : $text[$i+2];
$c4 = $i+3 >= $max? "\x00" : $text[$i+3];