I'm writing a mailing/discussion list application in PHP. I have outgoing mail working, and I'm capturing bounce messages. Now I need to figure out how to process those bounce messages, so I can remove bouncing email addresses from future mailings.
My client is currently using SmartList for the discussion list, and I notice that sometimes a bounce message will contain the entire original message, which in turn can include a multitude of quotes from earlier messages in the thread. Thus, there can be lots of different email addresses in the body of the message and all the quotes.
How do some of those commercial packages that can do this determine things like hard bounces, soft bounces, etc.?
Or to simplify, how to simply tell what address bounced?
Is there any current PHP script or class for doing so?