Site info : NopCommerce 4.30
We are under an important spam attack.
We received more the 5000 emails today from our web site using the contact email.

All captchas are activated but someone from a China IP seems to find a way to break the security.

Spam seems stopped, but I notice a uge amount of 404 errors in the log and it does not stop (1 every 2 seconds).
Errors target URL is : [siteURL]/productemailafriend/[productId]

What should I do ?

Thank you