Instead of searching for scripts about bouncing emails, then try searching for "pop" scripts. There are plenty of examples of that sort of thing. POP scripts can log into any mailbox you specify (assuming you know the password!), read the mail, parse it and perform some task based on the mail received.
Break what you are trying to do down into small steps and you should easily find the components you want.
- you want to be able to log into a pop3 mailbox
- you want to be able to read the contents of a mail into a variable
- you want to be able to parse that variable and make a decision
- you want to be able to remove an email address froma database
Doesn't it sound much easier like that? 🙂 There are POP3 functions here which should help you out with steps 1 and 2. Step 3 is nothing to do with accessing mailboxes and is just about parsing text and using some sort of logic to come up with rules to determine what to do based on the original text. Step 4 is just bread and butter database stuff.