I have also tried using inline CSS, but it hasn't completely resolved the problem. Could you provide details on which CSS properties are currently supported in the Outlook Windows app? Additionally, what are the best practices or workarounds to ensure emails display correctly in this environment?, To fix your CSS not showing in Outlook, you must write all the CSS in inline format. Otherwise, Outlook may not understand what styling you are implementing. Also, don’t use Divs in the structure; instead, use Table tags. Make a conditional statement with 650 width for better support in Outlook., I have seen the article, but it is not clear to me how this will solve my problem of forcing Outlook to use inline styles instead of css calsses. I cannot use the css classes in my java app to render the mail on web page as I will be recieving appends from multiple users with multiple styles definitions., I'm developing email templates and I need to use display:inline-block but it's not working on gmail and outlook. I just need to align an image with a text and I can't use a table . Any suggestions, Utilize inline styles: Email clients need inline styles, not web sites, which frequently make use of external stylesheets. The “style” tag must be used to directly incorporate your CSS rules in your HTML code as a result., For better compatibility across various email clients, especially different versions of Outlook, use inline CSS rather than external stylesheets. Outlook's limited support for certain CSS properties means that modern web layout techniques like the Flexbox, CSS Grid, and some properties of the DIV box model often don't render correctly..