One of the most common tasks that a PHP programmer has to tackle is the development of applications that send MIME email in one form or another. In simple terms, MIME email consists of an extension of traditional email technology and comes in handy for sending email messages in fancy HTML and handling file attachments in a wide variety of formats.

In this first part of the series he just lays the groundwork - creating the mailer class they'll use for the series and using it to send a sample email (a basic message with a plain text MIME block).

How do you get this [custom] XML to be output by the SoapClient?

Using the SoapVar method and a few newly created objects, making a custom structure is simple. It's just a matter of encoding the object and setting it with the base() method in the PHP SOAP extension. Check out the blog post for an example of both the custom XML and the code to produce it.