What version of HTML to use in emails?

Question

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

HTML 3.2
HTML 4.01 transitional
HTML 4.01 strict
XHTML 1.0
XHTML 2.0
HTML 5

What would you recommend me to use?

Answer 1

If you thought browser-html was fragmented, you're going to pull your hair out with email-html. You often don't have the luxury of providing a doctype (to distinguish between transitional/strict, etc)... even if you provide one a lot of clients will ignore it. This gets even more complicated when you have webmail viewers - those pages already have their own document type so they won't pay attention to yours.

Once you're past that (as in - don't even worry about it), you'll learn that very limited layout options are provided... CSS is only vaguely supported... and not by every client (excellent guide here). Table design will creep back in, and you'll find yourself weeping at the things you have to do just to get it to look readable (let alone get it looking similar across platforms).

It's not unlike trying to build a GUI application on the command line... or bringing a carrot to a sword fight.