Mail

If you have ever been frustrated by email clients, now is your chance to get even and dump those second-rate applications for your own smooth, sophisticated PHP based client. Read the Modes of Operation section, and then write your own client to suit your needs.

The chapter on Mail contains the following sections:
   In Depth
      IMAP
         Mailbox Functions
         Mail Functions
         Subscription Functions
         String Conversion Functions
         Other Functions
      Mail Headers
         Minimum Headers
         Additional Headers
      MIME
         MIME-Version
         Content-Type
         Content-Transfer-Encoding
         Content-ID
         Content-Description
         Content-Disposition
      Modes of Operation
         Offline
         Online
         Disconnected
         Temporary
   Immediate Solutions
      Installing PHP Mail Functions
         Windows NT
         Unix
      Sending Mail
         Sending One Mail
         Sending the From Header
         Sending Many Messages
         Sending One Message to Many
      Sending Mail with Attachements
         Selecting Test Data
         Gathering File Information
         Building MIME Headers
         Building MIME Message Parts
         Building Non-MIME Headers
         Sending the Mail
      Verifying Mail Addresses

Open Source Email is the quick start alternative to writing your own email client.