Weird e-mail error returns

I got a lot of messages like this since a while :

31

Many of them tell me that “Mx.google.com” could not deliver this message, is there a problem with my DNS?

Hi @mathieu2,

Are you able to share some more details on this? Is this when you send an email to an address on your domain? Are you also able to share the domain here?

You may also want to have a look at Troubleshooting Email Delivery Issues when using Cloudflare