DevShed has finished off their series looking at sending MIME emails with PHP in this new tutorial, moving the current code from the previous parts up to a fully PHP5 state.
While this mailer class can be used with small PHP applications, it lacks some important features related specifically to its object model, since it was built in PHP 4 from the very beginning.
They review the PHP4 version of the script first then move on to the process of porting it to a more standardized PHP5 structure and code.