what is the difference between the php imap extenstion and one of the mail classes?

Question

I need my application to send and receive emails on certain events. I think I would like to use a mail server also to implement an in-application mailing ability, like the ability to send/receive/delete messages in applications like linkedin.
What would be a good tool, a PHP mailing class, the imap extension, or are they not covering the same responsibility and they actually complement each other, and I should use both?

Answer 1

They complement each other. Mailing classes send out; IMAP functions are there to read a IMAP Mailbox (IMAP can also send, but for any bulk mailing concerns, a full-blown mailer class is the better idea).

If you want to create an application with an interface, you may want to check out existing PHP Webmail applications (see here for a good list: 10 AJAX-based & PHP WebMail Clients For a Great User Experience) to gain insights from, or build on.