Email Encryption

Secure email: Protecting your health and personal information

Arlington County takes your rights to privacy and confidentiality seriously. Our secure email system provides the convenience and speed of email communications, without sacrificing our commitment to protect sensitive health and personal information.

Arlington County Government employees can initiate encrypted email conversations with clients, partners and constituents to non-County email accounts (e.g., corporate, Gmail, Yahoo, Hotmail). This allows us to share sensitive information in a secure format accessible only to the person for whom it’s intended.

How to use email encryption

  • Once you receive an encrypted email from Arlington County, download the “message.html” file.
  • Open the message.html link, which connects you to the Arlington County Encrypted Email Portal.
  • To view your message, either setup a Microsoft (MS) account (useful if you communicate frequently with the County) or request a one-time passcode.
    • The one-time passcode expires 15 minutes after requesting it. The passcode will be sent to the email address of the original email.
    • With an MS account you’ll have to enter your password to log into the encrypted email portal and view the encrypted email (your password will work for future emails).
    • When signing up for an account, uncheck the box for promotional offers from Microsoft if you do not want to receive Microsoft promotional offers.
  • Replies, reply-alls or forwards from within the encrypted message will continue to keep the message encrypted for the life of the message.
  • Encrypted conversations have to be initiated by an Arlington County Government employee — you won’t be able to send an encrypted email first.
  • This PDF gives more detailed instruction on how to open an encrypted email from a County staff member, including on a mobile device

Authenticity of the email

  • Before you receive encrypted email, you should first receive a courtesy email from us stating you’ll begin receiving encrypted email from Arlington County. The message you receive should come from an “” email address.
  • If you have any questions or concerns about the authenticity of the email please contact the County staff person with whom you have been working.

Helpful reminders

  • Junk Folder: Activation emails for Microsoft sometimes land in junk or spam folders. If you don’t receive your activation email, check the junk or spam folder. Also, check the junk folder for any encrypted emails as well.
  • Mobile Devices: iPhone and iPad Devices require iOS version 6 or greater, Android requires version 4.0 for downloading and using the Microsoft Office 365 Message Encryption Application.
  • Downloading the HTML file: When using personal email accounts, you’ll need to download the message.html file. You’ll have to create an MS account or receive a one-time passcode to view the message in the Arlington County Encrypted Email Portal.