After an absence, what should be Good are now classified as Spam

After being away for two weeks, using my iPad for email, I returned home and, launching Mail on my Mac, every/almost-every email sent to my @me.com address is classified as spam. I must select them, daily, and declare them Good. They keep getting mis-identified.

This also happened a couple months ago. Then, suddenly, everything reverted to acting normally.

So far, that reversion is yet to occur. Any ideas as to why this has happened, and what I can/should do to correct it?

Mac Studio, M3 Ultra — macOS 26.5.1 — Mail 16.0 — SpamSieve 3.3.1

I’ve never heard of that happening before. Perhaps it’s not due to SpamSieve. Please use the Save Diagnostic Report command in the Help menu and send me the report file, as described here.