Microsoft is pushing out a new version of Outlook Mobile to a select number of handsets.
Build 17.6769.40522 of the app features much improved rendering of email in the app, addressing a long stranding problem, but the updated version of the app appears to be available to only some handsets, in particularly not to devices on the Insider program.
Other devices are still on Build 17.6769.40332 and as can be seen in the screen shot above (via the WC) has less than optimal rendering which needs a lot of scrolling and zooming when viewing an email.
Users on Windows 10 Mobile and lucky enough to not be on the Insider program can find the updated app in the store here. The rest of us I assume will have to suffer for a few more days.