Mail is STILL saving multiple drafts of sent email

My MacBook Pro mid-2012, on Mojave 10.14.4, saves multiple drafts while I'm typing an email and does not delete them after sending. In fact, there is usually one "final" one sitting on the desktop or in the draft folder when I go to shut down. I panic, check my sent folder to see if I actually sent it (always have) and then I delete the draft. This has gone on for a long time. I thought upgrading to Mojave would help but it didn't. That's a whole other story. My Mac acts like it's brand new and not in a good way. I'm continually redoing preferences and verifying trusted devices, etc, like this machine just landed from Mars. So not apple-like. Anyone have help on the Mail drafts issue? I'll get help in the store on the Mojave issues.