Yes, that's what I was plenty aware of. I failed to make the connection between spam (unsolicited email) and SPAM (the Hormel potted meat prduct), which was mentioned in the parent comment.

I'm just not always on my toes, it seems. I appreciate your apt hint.

Edit: Oh, I know why I didn't connect. I was thinking of those as ways to verify a sender's identity. By that operation, a consequence is that spam is prevented, but I was only focusing on the primary function.