PHPMaster.com has published the second part of their series taking you on a tour through PHP's IMAP extension and its use. In part one they introduced the extension and showed how to connect, get the folders/emails and view message contents. In this part they expand n that and show you how to work with the messages and attachments.
In the first part of this series I discussed how to connect to IMAP servers using PHP’s IMAP extension. In this part we’ll complete the series by discussing working with folders and reading email content. Let’s get started!
He shows how to work with the "flags" set on messages (read, unread, replied, etc) - pulling them from the server and using the imap_setflag_full function to set them. There's a quick mention of deleting messages with imap_delete/imap_expunge and a section on viewing and downloading the attachments to messages.