Mail app censoring my emails

My ISP force migrated all of their customers over to Gmail a couple years ago, but until today I hadn't had any problems. I was also getting the Warning about my network preferences preventing downloads. I unchecked all the various boxes designed to protect me on the internet, but I'm still having problems. It may have to do with adult content, but even that isn't clear (trust me, I'm WAY over 18!) I don't have an ad blocker running, or anything like that. And the only screening app running is Malwarebytes.

Any ideas? Bright or otherwise?