Referring to a CSS file in a HTML Email -

i have project on thymeleaf + spring mvc, , trying use thymeleaf send html emails.

i under impression thing had create template file, , pass parameters i've been doing regular pages. looks wrong. when that, doesn't apply css. (as matter of fact doesn't refer css file.) don't know whether google 1 removing css file or mail clients do.

it looks google encode class , ids of html elements, option using inline css or there way reference css file in html email?

<img src="some_url" class="ctowud"> 

above img tag looks on gmail. should though:

<img src="some_url" class="topimage" /> 

thanks in advance

unfortunately, linking external stylesheets in html email poorly supported.

also, gmail strips style tags both head , body, need push of styles inline before send, make sure gmail doesn't remove them.

campaign monitor has great css support guide outlines can , can't use across email clients.