Ask YC: Do you process bounced emails from your app?

Hi, we're in the process of building the bounce management piece for the emails that go out of our application. A key piece to make sure we don't look as spammers to ISP's. However, I have no idea where to start.

How do you guys process bounce emails for emails sent from your application. Any links to articles, tutorials etc. would be much appreciated. PHP specific articles would be even better.

Thank you.