E-Mail encryption

In the wake of the NSA affair and the ever-increasing threat of cyberattacks, it is certainly not a bad idea to encrypt one's emails. One of the options to do this is the S/MIME standard.

According to Wikipedia (https://en.wikipedia.org/wiki/S/MIME) S/MIME (Secure/Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of MIME data.

The principle of S/MIME is quite vividly described by Microsoft TechNet (https://technet.microsoft.com/en-us/library/dn626158%28v=exchg.150%29.aspx):

S/MIME (Secure/Multipurpose Internet Mail Extensions) is a widely accepted method, or more precisely a protocol, for sending digitally signed and encrypted messages. S/MIME allows you to encrypt emails and digitally sign them. When you use S/MIME with an email message, it helps the people who receive that message to be certain that what they see in their inbox is the exact message that started with the sender. It will also help people who receive messages to be certain that the message came from the specific sender and not from someone pretending to be the sender. To do this, S/MIME provides for cryptographic security services such as authentication, message integrity, and non-repudiation of origin (using digital signatures). It also helps enhance privacy and data security (using encryption) for electronic messaging.