> What’s the worst thing a spammer can do if they sign up? I have seen spammers signing up just to send short message via welcome email ("Hi firstname," -> "Hi

> What’s the worst thing a spammer can do if they sign up? I have seen spammers signing up just to send short message via welcome email ("Hi firstname," -> "Hi check this foo.com,") to their targets. The worst thing that can happen from that is that your domain/email servers end up in the blacklists.