In a support note, spotted by BleepingComputer, Microsoft explains that opening, replying to, or forwarding an Uber receipt email will cause this issue. Uber uses “complex tables” in its emails, and it appears that Microsoft Word, which Outlook uses to view emails, is struggling to render these tables.
“The Word Team has implemented a fix that will be released to the Beta channel shortly for fix verification,” explains Microsoft. “We currently estimate the fix to go out to production Current Channel on Patch Tuesday August 9th, 2022.”
IT admins can use a workaround to fix the issue, reverting to a previous build of Office that works fine with Uber emails. That suggests the issue was introduced by an Office update rather than a change in Uber emails. Either way, the problem should be rectified next Tuesday.