Enormous Mail Log and Endless Moving Messages in Apple Mail
My Mac reported that I was running out of disk space. Sure enough I had only a few gigs left free in my terabyte drive. Using advice, I found in another thread, I found Mail logs added to nearly 500 gigabytes. I deleted the two files, but a reboot or two didn't free up the liberated space after all. Fortunately, Disk First Aid fixed that. I now have use of that 500GB disk space again.
Seemingly unrelated, I had been problems with one of my Mac mailboxes not syncing properly with that mailbox on my iOS devices. In addition, that same mailbox reported little progress moving messages as shown at the bottom of the mailbox. I read about complicated and seemingly risky procedures to fix that problem. After clearing the log files, the message moving problem was still there. So, I left the app running over night and by this morning, the moving message and syncing issues were gone. I'm guessing that the two problems were related.
Perhaps it is time to cull more of the 43,500 messages in that mailbox, an AOL account dating back more than 30 years!
MacBook Pro 15″, macOS 10.14