Hey @Ieva,
Really appreciate those additional tests you’ve performed!
Sounds to me like your Outlook desktop inbox version is using Microsoft Word as its rendering engine. Whereas your online Outlook inbox is using Webkit, which explains why it’s rendering without issues.
It’s actually not uncommon for emails to look a bit off in Outlook sometimes. This is actually an industry-wide roadblock stemming from how Outlook renders emails. This is further explained in our My email looks different when viewed in Microsoft Outlook Help Center article in case you didn’t get a chance to take a look at it.
Ever since 2007, Microsoft/Outlooked switched from using Internet Explorer to render HTML to Microsoft Word which causes some known issues such as the following:
- No support for background images in divs and table cells
- No support for CSS float or position
- No support for text shadow
- Poor support for padding and margin
- Poor support for CSS width and height
- Problems with nested elements background colors
Litmus, an email preview software we highly recommend has a great blog article they written providing some tricks in combatting these difference: Outlook Email Rendering Issues and How to Solve Them.
David