And Mail won't import its own .imapmbox folders. Will drag them into EagleFiler to convert to mbox, then import the mbox files into Mail.
There's a backup from a couple days ago, but Mail's import command is confusing with double-click vs. the Choose button.
Wouldn't be a problem but for compulsive trash-emptying.
The downside of IMAP: Dad deleted some messages from Web mail, and now they're gone from his Mac.