What is a consent token?

Question

I think it deals with s*x? I'd appreciate it if someone can answer this for me.

Answer 1

People can agree, explicitly or tacitly, to accept email from each other.  To express this agreement they give each other tokens which are called "consent tokens".  Subsequent email from each party bears the token the other gave them, thus demonstrating that they are someone who has been granted permission/consent by the recipient.

Answer 2

nothing to do with s*x