Opening Mail App leads to endless Compose Mail Message Windows

I don't use the Apple Mail app, but occasionally the app opens automatically for various reasons. When it does so an endless number of Compose Mail message windows pop up. I assume this is related to some auto created email reminders or something like that. But it goes on seemingly forever and I have to force quit the app. I would like a way to clear out all of these. I tried deleting com.apple.mail.plist from the preferences but that didn't work.

See screenshot for all the windows popping up. Some but not all have this "Hide my email" in the from field, but it would take a very long time just to close all these windows.