There are times you have to send a message to a bunch of subscribers and need a very simple mechanism to allow them to unsubscribe from your list, something like a link on the message footer that will take the subscriber e-mail address and store it in some place so you can take it off your master list later.
This is a very simple PHP script (and an alternative to MLM) you can upload to your server to start handling unsubscribe requests from your customers in seconds.
It is called 'unsubscribe.php'. Look at the readme file in order to know how it works. This script is really simple and easy to modify in order to include more features. Currently it only stores e-mails so you can know which ones to get off your list (Our bulk Mailer is able to batch delete e-mails from such a list).
If you are using MaxBulk Mailer and you are looking for something more powerful, have a look at MLM.
This script is free for personal, non-profit and academic users as long as all copyright notices, and headers remain intact and unmodified in the source. Commercial users must register the script for a one time fee of $10 US: