[flashmob]

of course - create any website open to the public where they can message each other, and there will always be some abuse. It's unavoidable.

But what can you do? You can't police the messages for every potential form of abuse. (I've only ran an automated spam filter to make sure that the service is never used for blatant spam. I've also blanket-blocked some domains whenever I noticed a pattern in any abuse reports, and finally recipients were able to easily do a permanent block themselves). In any case, running a messaging service even more difficult if you're a small guy and not Facebook or Google.

I've added more information about the details of the suspension in another post on here: https://news.ycombinator.com/item?id=24998922

[GoblinSlayer]

I thought you allowed to send messages to guerilla addresses only, but you allow to send messages to the rest of the world? If you intend it only for replies, maybe check that inbox has a message that passed DKIM verification, aged no more than 4 days.

[user5994461]

You're being naive thinking you can run an open spam service with no consequences. Maybe you don't care about abuse but the hosting does and will act on the recurring complaints.

Seriously, cut the ability to reply to emails and that should be fine.

There's no use case to send replies for an anti-spam. Never seen a registration process that required to reply to complete the registration.

Tip: The google postmaster tool can show you the reputation of your domain and how much of your outbound emails are going to spam. That shall give you an idea how well it's abused. https://www.gmail.com/postmaster/

[flashmob]

It wasn't shutdown for spam, and the service is not a spam service but an ant-spam service.

The service has been sending out emails since about 2013. It only lets out a limited number of emails, and there's an anti abuse policy in place. The IP address always has a good reputation with Google and Microsoft, I am well aware of all the feedback loops.