Sending MIME email in PHP

Tired of sending those drab textual notifications and newsletters to your friend and clients? Ever wanted to send attachments and/or HTML embedded email.

The answer is MIME. The ensuing few pages explain the basics of MIME, creating MIME-compliant messages and then ends with a working class implementation of sending MIME complaint email in PHP. Note that references to calling script, caller etc. denote the script that uses the class we are about to develop and client/MUA etc. denote a mail reading client or mail user agent.