HTML being sent in plain text clients

Hopefully I can explain this correctly. I've been trying to setup the notification on my form with HTML, which works fine for clients that see the HTML.
When I check the message with an email client that doesn't support HTML - instead of plain text I see all the markup along with the text.

I've tried multiple things - disabling auto formatting and putting all in one long string, removing the html and using just text with auto formatting turned on, etc.

I can't seem to find the right combination on this. How do I set this so that email clients that can support HTML will see the HTML, and email clients that need plain text will see the text without the html in it?

Thanks,
Barbara

Hi Carl,
Thanks - I figured a work around for this that gets me through the problems.

Best,
Barbara

I second the vote for plain text support. My studio management software requires plain text emails for automatic submission. Having the option available can't hurt anyone, I would personally appreciate it.

Hi Carl,

I'd like to my vote to this feature request, with the following addendum:

I would prefer to see emails sent as multipart/alternative, with a text and an html copy of the email. This is really the best way to handle sending HTML emails, since it allows the recipient to view whichever version of the email he prefers / whichever version of the email his client can render.

This is also becoming more important with "DropBoxes", email addresses that process incoming messages and do something else with them. In many cases, these DropBoxes only work correctly with text emails. Sending emails as multipart/alternative would allow your customers to create rich HTML messages for correspondents who choose to view them while creating an alternate text version of each message for clients that can only handle text emails.

Multipart/alternative example at php.net.