As far as email spam, anyone who puts me on their mailing list because they met me or emailed me and i replied, any solicitation that isn’t customized to me, anyone who emails more than twice without me replying (just because you want to chat with me doesn’t mean i’m obligated to answer) to them.
On CAP, any post that isn’t really relevant in the thread and is self promotional. A self promotional post by an affiliate program even if on topic. Back when MGS announced leaving US, some folks posted a detailed description of your affiliate program that takes paragraphs to describe, that is spam in my book. A post saying: “our program will continue taking US players” is not spam.