[curtisblaine]

> Do we really need to send plain versions or it's just a second system syndrome of doing everything "right"?

It depends on your costs / target ratio. You will have a percent of users that absolutely need to get text emails. If delivering text e-mails to them gets you more money than you spend sending the two versions, send them. Otherwise, just send the HTML ones.

Same for browser support. If, for example, you spend more supporting IE than you gain from only-IE users, just don't support IE.

[gradschool]

I agree with the suggestion that you analyze how much of your sales are to customers who prefer plain text and assess whether it covers the cost of maintaining it. However, the numbers might not tell the whole story because some people deliberately block or ignore html mail even though they could figure out how to read it if they really wanted to. You probably don't monitor the replies to your marketing emails so you'll miss the replies requesting plain text format. (Nobody's going to look through your html code in their plain text mail reader to look for the url they have to copy and paste into a browser to access your web app that lets them change their email preferences to read your future marketing emails. They probably consider their time at least as valuable as yours.)

[notrheadagain]

Well, I agree here. However, it's pretty hard to include click tracking into plain text emails. So it may be complicating attributing revenue to those. The way out here would be utms or stuff like bit.ly