[@NowayJose] If you use this (or any other method) to encrypt an email (or any other type of file) for sending via the Internet, then, of course, you have to send the decryption key (or file, or token) to the recipient via a separate email, text or some other method, even a phone call. SilverKey is intended mainly for sending encrypted ‘packages’ of files (parcels) and is not the best solution for sending encrypted emails. If you want to send just encrypted emails, then I suggest you look into getting a “secure-email signing-certificate”. Comodo offers a very good one for free.