Smart Mailboxes disappeared
Suddenly Smart Mailboxes disappeared. I'm using Big Sur, so I thought some sort of bugs for new OS, but it seems like not OS issue. This morning I notice, so I checked El capitan mail and I saw there were Smart Mailboxes. Few hours later I checked again and found that were gone as well. I opened Macbook's El Capitan mail, it's also gone. I guess this could be iCloud issue, but I can't figure out yet. Is anyone having same issue and know solutions?
Mac mini, macOS 11.0