Sending unsecured email is very risky and in some cases even against company policy. One of the best ways to secure your email is by use of encryption. The sender types up their email and then hits the secure button or encrypt button depending on the email client used and then hits the send button. What happens underneath is that the sender’s text message is encrypted with their private key and when the recipient receives the email message they then decrypt the message using the sender’s public key.

Another approach to sending email in a secure manner is to use the Secure Socket Layer (SSL) connection. Two applications such as a client and a server will use an encrypted channel to send and receive information to/from one another. The application sends data through the SSL channel which itself is using the default TCP/IP port 443. Data passes through the secure channel so that both sender and receiver can read and understand the transmitted data. The secured channel protects the data from being read by an unwanted third party.

Another approach to sending secure email through an SSL channel is to encrypt the data with the public key of the specified recipient before sending it into and through the secured SSL channel. So even if the SSL channel is hacked or sniffed then the hacker still cannot see the plain text message because they would not possess the intended recipient’s private key needed to decrypt the message. This approach adds a second layer of encryption onto the email communication process if SSL is used for the communications. The result is that encrypted messages are sent and received within an already encrypted data communication channel.

It is possible to add a third layer of security to the email communication process by placing a central server – an email gateway – between the clients who are sending and receiving the encrypted emails through the already encrypted SSL channel. This server can act as a repository for the encrypted emails and forward them on to the intended recipients when requested to do so.

The benefit of such an arrangement is that the server only hosts the encrypted messages and can be used to keep costs and CPU cycles down to a minimum if such a server is hosted at another site by another company who specialized in this methodology. Remember that the private keys are not distributed so the hosted encrypted emails cannot be decrypted by any outside third party.