I like that it is easy to use, has many features including encryption for emails as well as files such as photos, documents etc.
The price can be expensive compared with other services out there but if you are looking into secure email transfers this may fit your needs perfectly. We have been able to send sensitive information securely without worrying about any security breaches or hacking of our data by using file mail. It also allows us to store all important customer info in one place so we don't need multiple spreadsheets/files which could easily get misplaced over time when working from home.