You can test it very easy. Try to not check the reCAPTCHA checkbox and register. If it returned an error, then it works fine.

Thank you for your explanation

Yes, I know and I read the activation system,

But Our web site traffic is not too much and I think those robots fill that form very easy

When I disable the option: Enable User Registration email confirmation, Those robots can't fill the registration form and it seems Recaptcha works great on the normal form including password

I like to have users with email confirmation, But it seems Recaptcha doesn't work properly on the form of USERNAME & EMAIL registration, However it displays the Recaptcha but it seems robots can bypass that and the server sends many email to filled email addresses which is not good

I know there are many powerful robots but I think this is not that case, Because those robots can't fill the normal registration form and our web site traffic is not heavy too

Welcome to spam reality! Please read the FAQ topic i shared.

reCAPTCHA works fine, reCAPTCHA is not 100% protection, lots of spambots can pass reCAPTCHA without any problem.  Spam is powerful and there is no way to stop them with any tools. You can make them less but you'll never stop them.

There is no any problem. All spambots are developed for the registration form which doesn't contain password field, and they expect confirmation email. The spambots don't work on this form, this is the only reason.

Thank you @robert for your reply,

But that form will fill by robots and the system will try to send many confirmation email

And those registrations will be as inactive status in the members area

I see Recaptcha on that form but it seems it doesn't work properly

is it possible to apply that in that form ?

Thank you for your support

But still we get too many new users registration with inactive status

What is wrong?

Nothing is wrong, Spam is very powerful. If you enable some form for user registration, you should use tons of plugins to protect your forum, please read this FAQ topic: https://wpforo.com/community/faq/how-to-stop-spam/

In the upcoming v2 major version, we've added a Manual User Approval system. So you can approve all trusted users and delete spam manually. If this feature is enabled, all new registered users will not be able to login and their statuses will be inactive. You can select them bulk and delete in Dashboard > wpForo > Members admin page: https://wpforo.com/docs/wpforo-v2/settings/login-registration/#enable-user-manually-approval-system

There is no any problem. All spambots are developed for the registration form which doesn't contain password field, and they expect confirmation email. The spambots don't work on this form, this is the only reason.

I found a strange things,

I was enabled the option : Enable User Registration email confirmation

So those robots can register as inactive users and the system sends emails for confirmation

But now I disabled that option and there isn't any new user

May be there is any problem in the form of User Registration with email confirmation

Bots can't usually bypass recaptchas, but real users of cource can.

If you have an abusing domain like the one you posted, then block it. Simple as that.

I have always been suggesting to protect Wordpress sites with some security plugin, for me akismet and recaptchas do not work very well.

How they can bypas Recaptcha ?

Disabling that option will increase spams by sure

What we can do against those robots?

They are mostly from @inbox.imailfree.cc domain !!

Thank you for your support