Kostadin, I think León gave you a piece of the answer.
Your real value proposition is that you keep mail from getting hacked--something that happens to far too many people. Once you've qualified people with an interest, then the secondary benefit comes in. If yours is easy enough to use that even older executives can do it--they sometimes barely know how to use a computer because their secretaries have handled everything for 30+ years--then you have a clear point of differentiation (a USP).
BTW, I'm very good at helping companies identify benefits in their marketing. If you'd like to know more about my services, please send me a private note.