I built a discourse today but get many new user registration spam. [image] [image] Many are from the same IP and they don’t pass the email verification. Due to the limited email I can send a day (a free plan), how to prevent this kind of spam? For example, add a CAPTCHA when signing up? Than…

Even though they can’t post, they do some random things such search queries, [Screenshot 2025-03-17 at 4.34.59 PM] or seemingly trying to hack the auth system: Job exception: Net::SMTPAuthenticationError (google_oauth2) Authentication failure! invalid_credentials: OAuth2::Error, invalid_grant: B…

I suggest adding qq.com to the setting email domains blacklist.

But the man change to @126.com and continue spam..

Yes, they may or may not. Until it happens it’s just a theoretical problem. Most of the time this is all automated spam, so it’s unlikely to happen unless another bot targets you. You may also disable email signup and restrict to social logins (Twitter, Facebook, Google, Github, etc) which doesn’t …

Can we add CAPTCHA before sending email verification?

No better idea? I think it’s a basic issue of anti spam but no solution in discourse amazingly.

Can you provide more detail? Did you blacklist both of the problem email domains as requested?

@codinghorror Yes, after blocking this mail address, the spamer will change to another address like @126.com, @gmail.com, @icloud.com and continue signup new users with bot.

Seems these signups are coming from the same IP address ? Something would probably need to be done there. Block an IP address after x signups during a certain time frame ? Or forbid another signup from an identical IP address for some time ?

@Mevo But when I block and delete these IP, the spamer begin to use proxy to change his IP constantly and sign up new users.

How to prevent registration spam

Support

livc (Armin Li) October 7, 2019, 4:45pm 6

By the way, how to disable email signup and only allow new user from social login?

Anyway to only allow new user from social login?

Topic		Replies	Views
A recaptcha plugin? Support auth-plugins , spam	2	188	March 20, 2025
Just had about 38 bot accounts and posts sign up and spam in the space of 30 mins Community Building spam	12	528	October 12, 2025
Registration challenge to stop spam registrations Support spam , signup	6	129	June 2, 2026
Is anyone experiencing an odd spam user attack? Any way to block? Support	14	446	June 7, 2026
Tips for Preventing Spam Site Management moderation , explanation , spam	14	5277	December 1, 2025

How to prevent registration spam

Related topics