Why are emails showing ‘null’ in the body when using Outlook?
We've been facing an issue where emails we're receiving appear with 'null' in the body text. This has been happening for about an hour. Interestingly, when we check the Mimecast records for these emails, we can see the full body text. Forwarding these emails back to their original destination seems to work fine. This problem isn't isolated to just one mailbox or one sender; it seems to impact multiple users across our tenant. Does anyone know why this might be happening?
5 Answers
These outages seem to hit Outlook at random. It's almost like it decides certain emails are a hoax! You might want to try restarting your systems, but honestly, it feels like a larger issue that needs fixing from their end.
We've been impacted too—we're using Mimecast and Microsoft 365, which keeps the received view intact but mistakenly nullifies the delivery view. If you need to access the text immediately, try downloading the email in .EML format and opening it with Notepad; it’s not ideal, but it gets the job done for now.
Same here! The emails come through Mimecast fine, but then they show 'null' when they land in O365. At first, we thought it was just a few clients, but seems wider spread.
Yes, I've noticed it too. We're also using Mimecast and O365, and it seems like it's affecting the HTML emails inbound primarily. Mimecast hasn't reported any major issues, though. Weird, right?
I'm experiencing the same issue with Mimecast in the mix here in the UK. It's definitely annoying!

Mimecast said they expect it to be resolved soon. Let's hope that's the case!