Rated 5 out of 5 stars

by Josh on Dec. 4, 2015 · permalink

From what I can tell, this is the only add-on that supports client side DNSBL checks. It comes with a pre-loaded list of DNSBL servers but what I really love is the option to add custom ones. You can even add several.

SPF checks also comes in handy, I already found some misconfigured e-mail servers for some of my friends!

Good job!