Security gateway is a very well developed tool. You have access to a number of tools such as anti-virus and malware scanning and spam filtering. This tool is easy to use and setup. Also it gives you the ability to configure rules and policies. The pricing plan is reasonable and you can purchase add-ons if required. The admin interface is pretty easy to understand and use. However there is a bug that prevents me from adding custom domains to the configuration file. Also, although the tool does have a built in virus scanner, it is not very effective. It will block legit emails but will let through malicious ones. Also, the API is quite complicated and it's difficult to get information about any given domain. In addition, I am unable to change the IP address range that I am allowed to see and I'm not able to set specific IP addresses to exclude from being scanned. Overall, I would recommend this product to small businesses looking for a cost-effective way to protect against email threats.