The Hall of Heroes for Mutants and Masterminds character sheet group that I am a moderator for, all first mailings must be approved and the moderator can then go in and change the membership to allow that person to post without moderation in the future.  If it is a Spam there is a delete as spam button to dispose of the unwanted mailings.  You can then delete the account, or set it so the member can no longer post to the group.  I primarily use the cannot post button to avoid the spammer from resigning up and dumping another spam on the moderators. Maybe the mod.s here might want to reconsider how this works, of course I am fairly certain M&M character sheet gets less traffic than HeroForge, but who knows. Brian