Rob Allen has a quick tutorial posted to his site today showing you how to send an email with the ZendMail component of the Zend Framework 2 that contains HTML but provides a plain text backup in the same message.

Sending a multi-part email with ZendMail is easy enough, but if you want to send an HTML email with a text alternative, you need to remember to set the content-type in the headers to multipart/alternative. As this is the second time I had to work this out, I'm noting it here for the next time I forget!

The rest of the post is the code you'll need to send a simple email with a text and HTML body sections, configure the headers (to, from, etc) and the "multipart/alternative" header to make the HTML or plain text switching work correctly.