How would I test rblserver?

Question

I'm using few rbl servers, and all of the sudden i see slowness, as soon as I remove all rblservers, it works very fast as it used too, other than removing one by one server is there a way to test rbl server somehow?

Answer 1

Typically RBL servers operate over DNS, therefor any slowness would becaused by DNS. From there, perhaps BIND has a logging option that will tell you name server lookup timing -- but I am not aware of one. You could use a query log to manually test the queries with DIG, or have a cronjob that randomly queries each RBL with a test domain, and pragmatically disable any slow resolvers.