Password Protect and Encrypt Your Email in Windows

Step-by-Step Instructions

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If you don't want other people who have access to your computer -- legitimate access, of course, because they're family, friends, and colleagues, for instance -- to have access to the emails it holds, you have set up a distinct Windows account for each user so that everybody can have their own wallpaper, and so that emails and documents are kept separate. This is very well and good, but it is not enough to protect your emails.

Keep Your Email Private in Windows

To keep your emails -- even as files on the disk -- private from the eyes of other users:

This prevents other users from all access to the folder. You mail is safe as long as nobody can log on to your Windows account.

Make Sure Automatic Windows Log-On is Not Enabled

For Windows to log on a particular user (you) when it starts up automatically is convenient but it lets whoever restarts the computer get to your mail. Here's how to disable that behavior:

  • Select Run... from the Start menu.
  • Type "control userpasswords2".
  • Click OK.
  • Make sure Users must enter a username and password to use this computer is checked on the Users tab.
  • Click OK.

Make Your Screen Saver Require a Password

Now let's make sure Windows logs you off (in a way) even when you don't. If somebody came to your computer while you are logged on but you're not there, they could comfortably access all your emails otherwise.

  • Click the right mouse button somewhere on the Windows Desktop.
  • Select Properties from the menu.
  • Go to the Screen Saver tab.
  • Select any screen saver.
  • Make sure On resume, display Welcome screen or On resume, password protect (whichever option you have) is checked under Screensaver.
  • Click OK.

Encrypting Email Messages

Encrypting an email message protects the privacy of the message by converting it from readable plain text into scrambled cipher text. Only the recipient who has the password / private key that matches the public key used to encrypt the message can decipher the message for reading. 

Important things to note: 

  • Sending and viewing encrypted email messages requires both sender and recipient to share their digital ID or public key certificate. This means that you and the recipient each must send the other a digitally signed message, which enables you to add the other person's certificate to your Contacts. You can’t encrypt email messages without a digital ID.
  • If you send an encrypted message to a recipient whose email setup doesn’t support encryption, you are offered the option of sending the message in an unencrypted format.
  • This process also encrypts any attachments sent with encrypted messages.

Encrypt Your Mail Files and Folders

If you could not make the files used by your email program private using the method above:

  • See if your email program allows you to move the files to a folder beneath "\Documents and Settings\[your user name]\".
  • Proceed with the method outlined above.

Should that not be possible, or if you want to be extra safe and encrypt the files on disk:

Remember that emails that are not themselves encrypted before they are sent can be intercepted and read. Protecting files on your disk only prevent others from accessing the mail as it is kept in your email program.

Encrypt in Outlook Express

Here's how to password protect and encrypt in Outlook Express, Outlook 2007 and Outlook 2010.