Exim incorrect password delay

[cmelcher]

I am having a lot of brute force attacks, and DA/CSF is blocking them as programmed. However, in the 2 seconds it takes DA/CSF to restart iptables and block these attacks, these scripts can try logging into exim 40-60 times.

How can I set a 1 second delay between login attempts so that this scripts can't try 50 logins per second? Is this a bad idea?

Thoughts?

 

[zEitEr]

Hello,

However, in the 2 seconds it takes DA/CSF to restart iptables and block these attacks, these scripts can try logging into exim 40-60 times.

Why do you need to restart iptables? There is no need to restart iptables if you want to (un)block any IP.
Also if you really need to restart iptables, then you might need to use

csf -r

instead as recommended by CSF instead of

/etc/init.d/csf restart