How to "filter unknown sender" in Messages on my Mac?
I set up "filter unknown sender" in Messages on my Mac desktop the other day. It took a while, but I like the feature on my phone, so I wanted it on my computer. I found a helpful article online, and it worked. Today the split list is gone on my computer's Message app; no "unknown sender." And, I can't find that article again - not in my history, not in any searches. Did I dream this? Any ideas what I can do?
iMac 21.5″, macOS 10.12