I like that it is easy for employees to use as well as customers/clients since their interface is very intuitive. It does block most viruses but not all so you always need to monitor what's going through in order to make sure nothing slips past. We have been using this product with our email servers for nearly 10 years now. The only thing we dislike about it is how slow it can sometimes be when sending large files or attachments which makes it hard for users to send them over email quickly…