Encrypting Your Email

If your email contains sensitive or confidential information you have the option to encrypt the contents of your email. If your email contains personally identifiable information (PII) or Financial Data (Ex. Social Security or Credit Card numbers) the email must be encrypted prior to sending or you may recieve an "Message Undeliverable" error.

'Message Undeliverable' Error

If after trying to send an email in Outlook you receive a 'message undeliverable', 'message undelivered', or 'Your organization won't allow this message to be sent' error, your email may contain content that appears to be sensitive or confidential. Office 365's data loss prevention (DLP) feature prevents sensitive information such as financial information, personally identifiable information (PII), or intellectual property data from being accidentally sent to unauthorized users. Depending on the type of confidential data that is included in the email you will receive one of the following messages:

Personally Identifiable Information (PII)

Attention: The automated email scanning system has detected an attempt to send a message that contains a Social Security number. NRS 603A.215 does not allow Social Security numbers to be sent via un-encrypted email. Please re-send your message without any Social Security numbers in the message or contained in the attachment. Alternatively you may include the phrase “[ENCRYPT]”, without the quotes, in the subject line to automatically encrypt and deliver the message. If you believe this message to be in error or need additional assistance please contact the helpdesk at x25000. University of Nevada, Reno IT security@unr.edu

Financial Data

Attention: The automated email scanning system has detected an attempt to send a message that contains a credit card number or other sensitive financial information. Please re-send your message without any credit card numbers or other financial account numbers in the message or contained in the attachment as email is not an approved method for sending or receiving this type information. If this was an error and your email message and corresponding attachment does not contain this type of information, you may proceed with sending the email by including the phrase "[ENCRYPT]", without the quotes, in the subject line to encrypt the message. If you need additional assistance, please contact the helpdesk at x25000.


To verify you are receiving this error message due to confidential information, send a test email (one that does not contain the same content as the undeliverable email) to confirm that all other emails sent by you are successfully reaching their destination. If the email does contain sensitive or confidential information, you will need to encrypt your email as described below. 

How to Encrypt Outgoing Emails

To encrypt the contents of your email, write [encrypt] (with square brackets) in the subject of your email. Our mail server will detect it and apply secure encryption to the email.

Screenshot of a New Email message in Outlook

What Does the Recipient Receive?

  • When the encrypted message arrives, it will look like a regular e-mail (with an attachment). 

    Screenshot of a Gmail message line.
  • However, instead of the body of the message that you sent, this e-mail will ask the recipient to open an attachment. 

    Screenshot of an Email Encrypted using the Office 365 server.
  • The attachment (a simple html page) will instruct the user to follow one of two options to read the message. They can either create an account using the email that received the encrypted message, or use a one time code that will be sent to the same email address as the encrypted message.  

    Screenshot of the Encrypted Message Attachment.
  • The link takes them to a secure site on a University server, where they will need to register their details.
  • After registering, they will be taken to the message.

    Screenshot of the de-crypted email message.
  • This encryption prevents the message from leaving the University (the recipient can only access the message on the University server).
If you have any issues encrypting outgoing email, please contact the OIT Support Center.


Article ID: 117058
Fri 9/25/20 2:06 PM
Fri 4/9/21 4:06 PM