I have created several emails in RTM with conditions based on Attributes on Contact table. After sending these emails, they are not correctly displayed in Outlook, but e.g. in Yahoo. 

Result after checking by MS support: These issues occur in Outlook with the images, buttons and few other things in Real time Marketing as of today.

Thus I suggest the improvement of the email designer, to make sure, that the emails are crorrectly displayed in outlook.

This is high priority from my point of view, as most email recipients in the B2B segment use Outlook.