Jul 15, 2015

Can you hide the subject or other email message metadata when you send an encrypted message?

Most products show the subject line in clear text, so the answer is no. This means that some authority that can access your email store might not be able to read your message traffic but could gain valuable insights into what you are communicating about with this meta-information.

Some encryption products, such as Hushmail, use SSL to encrypt messages entirely if the message passes from one Hushmail user to another, but once a message passes outside its domain the subject is no longer encrypted.

One notable exception is Tutanota, which also encrypts the subject line, no matter who receives the message.
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