The customer support is fantastic! They are always willing to help us with any questions we have. I've never had an issue that they haven't been able to answer in a timely manner. There is nothing really I can think of that I dislike about this tool. It's easy to set up, easy to use, and it does exactly what it says it will do. We're using MX Toolbox for blacklisting domains. Prior to using this service, we were experiencing issues with sending emails through our ISP. Using the filters provided by MX Toolbox, we've found that we no longer receive bounces from those IP addresses and are able to send out emails without problems. The ability to get the most bang for your buck with a single platform, and using only one tool for all of my needs. I'm able to use MXToolbox as an anti-spam solution, antivirus/antimalware solution, and even a website firewall. It also allows me to monitor my network remotely from anywhere I have internet access. There isn't much that I dislike about this product. The interface could be more intuitive, but it's not too difficult to figure out. This gives me complete control over my network security.