Blocking large amount of spam domains

Hello,
I am using this suggestion below from a forum member on how to block spam domains.

Specifically this rule:

But in my country we have received a very large amount of spam!
So much so that this list of domains currently has 2000 lines.

We have already used all other methods available in the cpanel against spam.
And we also block a large number of IP numbers.

My doubt is the following: this blacklist of domains will be a very heavy job for the server to process in each email?

 

Thank you webhostuk! The performance of a large list really worries me about using this method.

Hello Michael!

In fact I do not have spam issues with new domains "yet."
But I'll consider using it in the future if it turns out to be a problem. Thank you!

My problem is very specific: regional spam

In my country (Brazil) there are no RBLs for spam in our region.
And the international RBLs do not catch the majority of Brazilian spammers.

And the spammers here are very aggressive, they send a huge amount of traffic every day.
You see, I have a list of 2000 confirmed spam domains that I created myself. That in a few months!

The best way I found was to block domains, beyond the IP ranges.

 

This is a good option siriusb. I'll consider create a RBL for my country, thank you!