Sending, receiving, and organizing email in Outlook.com
Hello,
Since you are using Outlook.com on the web, this is most likely a browser or message-rendering issue.
First, open one of the blank emails and click Reply or Forward. If the content appears there, the email itself is intact and the problem is with how Outlook.com is displaying that message.
Then sign out of Outlook.com, clear your browser cache, close the browser completely, and sign in again. Also test Outlook.com in another up-to-date browser such as Edge or Chrome. Microsoft notes that browser extensions/ad blockers can interfere with Outlook.com, so temporarily disable them as well.
Microsoft guidance:
If this only happens with emails from one particular sender, the sender’s email formatting/template is likely the cause. If all emails remain blank in multiple browsers, please let us know