Ability to Edit Text Version of Email

Here's what one of my contacts just said about Constant Contact's Plain-Text email:

"The minute I opened the year-end message, I saw that yet another of

the 501C# orgs that I support is being disserved by Constant Contact.

"Their disdain for your email results in me getting the message 
reproduced below. For security reasons I use a text-only mail reader.
Constant Contact sends multipart-alternative messages supposedly to
provide plain-text mail in addition to pretty HTML. But the way
they extract plain text would draw a low grade in a freshman
computer-programming course: simply run together all the text
parts of the HTML. Any beginning programmer could do a better job
with a few hours work. Their dereliction reflects badly on
their customers."