For those who use PLESK and have enabled maps spam protection, what servers do you use and have you noted a difference?

I am not very knowledgeable when it comes to this so can you list a few servers for me to use.

Thanks,
Brett

Plesk recommends relays.ordb.org or bl.spamcop.net - I've gone for ordb.org personally.

It's a difficult one because ordb only blocks open relays not known spam abusers.

Whereas spam cop blocks known abusers but doesn't offer much future protection from open relays.