New Mac Mail messages going directly to Archive

I’ve noticed recently that many of my new messages, addressed to my @mac.com account are going directly to the Archive folder. I see the alert from SpamSieve, but the message is in the Archive folder. I can’t find any rules which would do this. Is SpamSieve doing this?

No, SpamSieve never moves messages to the Archive mailbox.

What does the alert from SpamSieve say?

I don’t see a message from SS, the icon just bounces in the dock.

Thanks,
Steve

SpamSieve will bounce its Dock icon if there’s a window that requires your attention (e.g. Software Update). If you don’t see such a window, it’s probably just notifying you of new good messages.