15.0 Introduction

PHP offers support for reading and manipulating e-mail through the IMAP library, which enables you to access IMAP, NNTP, and POP3 servers. If you want to send email, you can either use the built-in mail() function, which is compatible with both Windows and UNIX systems, or you can write your own SMTP mailer.

IMAP, or Internet Message Access Protocol, was developed at Stanford University back in 1986. It has been ”until its recent introduction into the commercial market ”entirely freeware, similar to the more popular and simpler POP, or Post Office Protocol. IMAP, in the most basic sense, provides an interface enabling you to send and receive email. More information about IMAP can be found at http://www.imap.org.

PHP has excellent support for IMAP, with (at the time this book was written) more than 50 different functions for manipulating IMAP streams, making it one of most full-featured extensions in PHP.

The IMAP client library allows you to access both POP and NNTP servers. This means that you can not only access all the major mail protocols (SMTP via Mail_Sendmail ) via PHP, but you can also access newsgroup servers. For more information on accessing these different protocols via the IMAP extension, see recipe 15.1.