A recent conversation about the vagaries of HTML e-mail on the Progressive Exchange mailing list prompted some good conversation about a perennially vexing topic: how do you keep your hard-won html design rendering properly in your recipients' mailboxes?
Short answer: you probably don't.
For coders who like to get into it, I've been in the habit of recommending the exhaustive sleuthing done by sorta-competitor Campaign Monitor (for instance), which blogs the bejeezus out of the issue and has great resources like 30 free design-compliant templates that might shortcut the process.
The thumbnail version for the rest of us is that there's no orthodoxy. Like 4th century heretics, every e-mail provider has its own slightly different standard which on pain of hellfire and junk filtering is incompatible with every other provider's standard.
What's a small organization without the luxury of coding line-by-line styles to do?


On the orientation-to-Salsa 

Del.icio.us/DemocracyInAction
Myspace/demaction
YouTube/demaction
Flickr/democracyinaction