how to change the default "move" folder in Apple Mail?

I use rules to automatically direct lots of mails to a folder where I will read them when I see fit. But my inbox still gets tons of mails that I want to see immediately. I archive lots of these mails, in a fairly large set of folders (e.g. one for each client or course). "Cleaning up" my inbox means: clicking on the "move" button and then choosing the right folder. Since Apple Mail was set up to "guess" the folder in which I would want to archive my mail, life became a lot easier: for most mails, one click was enough.

But archives tend to grow big, so I moved the larger mailboxes out of my IMAP-account and to a place on my Mac.

Unfortunately, Apple Mail keeps suggesting to send mails from a known sender to these archived mailboxes. So now, for each mail, I have to correct the suggestion and indicate the right mailbox each time. Like in the old days...

My question is : how to tell Apple Mail that I want to change its default guess?

This question has been asked here before, and supported by 217 or so other users. But it was not answered. "Mail will learn after a while...." is simply not correct: I've been waiting for months now. And "check the support page on how to work with Mail" is hardly an answer.

So thank you very much for looking into this again.

(I use an iMac with Mojave 10.14.6 to keep track of my mail.)