What version of HTML to use in emails?

Question

What version of html would yo recommend for mail content to get best mail-client compatibility?

HTML 3.2
HTML 4.01 transitional
HTML 4.01 strict
XHTML 1.0

Answer 1

Since you don't control the doctype, you don't really control this. If your message appears within a web-based service, you get the type THEY'RE using.

To make matters worse, Outlook uses the MS-WORD engine for HTML rendering.

You're best to use this chart to decide which features to use when coding your emails and just pretend it's still 1999 (table-based designs, no background images).