Is Mailbait still a threat?

Question

Is Mailbait (or similar services) still a threat, was it ever a threat, and if so how can it be mitigated?

Mailbait is that service that promises to fill up your email inbox by sending you a huge amount of spam. Apparently it automatically subscribes you to several mailing lists. It's meant for "testing purposes", however an attacker can use it to DoS somebody else's email address. I haven't tested it. Online you can find people that say somebody used their email address on Mailbait, and they started to get so many emails that they even exceeded the maximum allowed incoming rate, even if the spam filter was blocking the majority of them. On Gmail by the way, not on some crappy email provider. However you can also find people that say they tried that "service", and it didn't work (maybe because they had a different spam filter that was blocking all of them, or maybe because spam filters had been updated in the meantime?). Most comments tend to be pretty old though (some years ago), so I'm wondering if it was ever a serious threat and if it's still an issue.

Answer 1

Whether or not those services are a threat is subjective and depends on your threat model. Whether or not they exist and can DoS a victim's mailbox with varying levels of effectiveness is not. Those services do exist and they can completely flood and deny service to someone's mailbox. In fact, you do not even need to use those services. For a long time, there have been quite a few ways to screw someone over, including manually signing them up to a large number of spam lists, or publishing their email in plaintext in comments on heavily-spammed or spun blogs and fake articles. It's the digital equivalent of signing someone up to receive a hundred free Bibles or delivering a dozen pizzas to their house. While I can't say if Mailbait works, the concept of DoSing someone's mailbox by getting them on spam lists does.