exporting indesign to email need help

Sorry, can’t help with the actual problem, but I might be able to help others read it more easily:

ok i created a flier with the program indesign.
it only includes 9 pictures and 2 small boxes with text.
i export it to html with indesign built in css.
i then edit the html and copy and paste the css file info inside html because i am working with a real estate company and i am in the middle of an email blast,
but html code points to a css file in another location.
so i open up the css file added the info directly to the html,
and then i copy all the html code directly into constant contact and mailchimp.
they both preview just fine everything was in the correct order and appropriate shape and size.
but when i send a test email to my gmail account and hotmail account it look all out of order.
if i remove the css it all look out of order regardless
any help what exactly i am doing wrong ?
i am willing to post the html and css coding if it will help.

Right: InDesign’s HTML export is NOT meant for email. InDesign only exports text and graphics, not page geometry (where everything is on a page). See:
https://creativepro.com/making-e-mail-blasts-from-indesign-documents.php
or
https://creativepro.com/exporting-and-importing-html-with-indesign.php