How to Open Encrypted Emails In Gmail & Outlook

April 9, 2019

10:00-11:00AM PST

If you are under the assumption that the emails you send and receive are encrypted, you are mistaken. The most widely used email platforms, such as Outlook, Gmail, and Yahoo don’t automatically encrypt emails. Many security-conscious individuals and businesses are casting an eye towards email encryption as a way to bolster the security of their data. In today’s society, it is absolutely essential that you try to minimize your security risks when it comes to malicious hackers.

Email encryption for your Gmail or Outlook account is a complex topic that has many facets. Important among these is how to open an encrypted email. Since many platforms like Gmail don’t have native encryption capabilities, opening encrypted emails can be a challenging process that is unique to each sender. Other platforms like Outlook offer a way to set up encryption, but this process takes a lot of coordination between the sender and recipient ahead of time.

In this article, we’ll outline the basic steps of opening an encrypted email. In doing so, we’ll break down what encrypted email is, why you might consider utilizing encrypted email, and how it works on a functional level on the most popular platforms. The truth is that sending and receiving encrypted email is often an unwieldy and inconvenient process, which is why so few organizations regularly encrypt emails. It's also hard to understand.

Trustifi is a third-party alternative that offers seamless email encryption that avoids many of the pitfalls of standard encryption methods. If you have ever tried to figure out how to open an encrypted email in Gmail, you will immediately understand the need for utilizing an external service to handle encryption. As we will see, encrypting emails on most platforms is neither intuitive nor seamless.

What is Encrypted Email?

Let’s start with the basics. Most people or users don’t understand what encrypted email is in the first place, so they simply assume that this security service isn’t for them. Encrypting emails in Gmail and Outlook is the process of scrambling the contents of an email message. To reconstruct the message, the recipient needs a key. Think of encryption as a lock and the key as a way to access the information. To an individual without the key, the contents of an encrypted message can’t be accessed. Once you have the key you can access the message easily.

There are two types of encryption for email that are in common use today. The most common type that you will find is known as public-key encryption. Less common, but arguably more robust, is symmetrical-key encryption. We’ll go over both of these standards to give you a better idea of what is required to open an email.

Public-key Encryption

Public-key encryption actually relies on two sets of keys. As the name would suggest, one of these keys is publicly available. The process of maintaining and storing public encryption keys is known as Public Key Infrastructure (PKI). In this type of encryption with S/MIME (Secure/Multipurpose Internet Mail Extensions) technology, the sender has both a public key and a private key, which is also referred to as a digital ID, digital signature, or digital certificate. This digital signature can be acquired through an external third-party that validates the identity of the other individual or business. This external third-party is known as a Certificate Authority. It is important to not think of a digital signature as the same type of signature that you sign all of your emails with. Rather, a digital signature has a vital authentication function for the purposes of sending a secure email through encryption.

With an encrypted email that utilizes PKI, the recipient must already have the sender’s private key on file. This usually works by sending an email with the digital signature attached to the recipient prior to sending the encrypted email. When the actual encrypted email is sent, the recipient will verify that the public key matches the private key by comparing the hashes, or a short string of numbers, in both. By comparing both the publicly available key and the private key they were already sent, the recipient can authenticate that the sender is who they say they are and can open the message.

Symmetric-Key Encryption

Symmetric-key encryption is less common in the public email sphere, but much more common in the defense and military sphere. At a basic level, symmetric-key encryption relies on a single key to encrypt and decrypt messages. In order for symmetric-key encryption to work, both the sender and receiver must have the appropriate key. Depending on the level of encryption used, if a third-party doesn’t have the correct key it is essentially impossible to unlock.

The highest level of symmetric-key encryption currently available is the Advanced Encryption Techniques (AES) 256 bit. This is the level of encryption utilized by the U.S. Military, Department of Defense, and other Government Agencies. This level of encryption is so strong that if an outside party doesn’t have the key, breaking the encryption would require more computing power and electricity than currently available on the planet today.

Opening an Encrypted Email In Gmail And Outlook

Now that we have a basic understanding of the components of encrypted email, now we can finally discuss how to open an email in Gmail and Outlook with this extra level of security. There are different ways to open an encrypted email depending on the type of encryption used. Both types of message encryption methods will require you, as the recipient, to already have a key. For opening an encrypted email in Gmail and Outlook sent with symmetric-encryption, having the key is all you need to decrypt the email.

For opening an encrypted email sent with public-key encryption, the process is a bit more complicated. You will already need to have the private key, or digital certificate, of the sender saved on your computer. This will then be used to validate the public key for that sender. Comparing both of these will allow you to authenticate the sender and open the encrypted email.

Opening an Encrypted Email in Outlook

So how do you view an encrypted email in Microsoft Outlook? If you or your organization is a Microsoft Office 365 subscriber, you can send and receive encrypted emails to other subscribers using Office 365. Opening these emails is relatively straightforward. Rather than requiring you to have a private key saved on your computer, Outlook will authenticate you in a different way. When using Office 365, you’ll be sent an email with the encrypted message as an attachment. Opening the attachment brings you to a sign-on page. On this page, you can either sign in and view the message by using your organization’s credentials or receive a one-time passcode that authenticates you as the recipient, which is how you properly open an encrypted email in Outlook. 

Opening an Encrypted Email In Gmail

So how do you open an encrypted email in Gmail? You're able to send encrypted emails in Gmail with the help of their confidential mode. You must turn it on in the bottom right of the window, and set a password and an expiration date for your email address. You have the option to choose "SMS passcode" or "No SMS passcode".

If someone sends you an encrypted email via Gmail, you can open the sent email and its attachments until the expiration date. You may need to enter the passcode if the sender selected that option so you can open the encrypted email in Gmail.

How to Open an Encrypted Email Sent Through Trustifi

The reality is that email encryption is often too much of a hassle for most people to set up and use, which is why we so rarely see it in our personal email inbox despite its advantages.

That’s why Trustifi developed a simplified process for sending and receiving encrypted emails and its hassle free nature is one of the biggest advantages.

Opening an encrypted email sent by a Trustifi user is very simple. First, understand that the recipient doesn’t need to have Trustifi installed in their web browser. When an encrypted email comes in, they can click on the email. This will bring them to a page where they can complete an easy 2-factor authentication process. Once authentication is complete, the recipient can open and view the encrypted message. From the same page, the recipient can reply and send an encrypted reply back to the original sender.  

Closing Thoughts

Encrypted email offers some enormous advantages in terms of privacy. Today’s email inboxes, whether they are our personal email or an institutional email, are a key area of vulnerability. This vulnerability exists when the email is in-transit to its destination and once it arrives. Encryption ensures that even if an email is intercepted on its way to its destination, there is no possible way that the malicious actor that intercepted the email can open it and view its contents. Encryption also ensures that if an encrypted email is sitting in the destination inbox and the login credentials of that inbox are stolen, no one other than the intended recipient can access the information.

Given the obvious security enhancement that encryption offers, you might be wondering why it isn’t a more common service. While modern encryption is very strong, it is also often inconvenient for both the sender and recipient. The most common form of email encryption in use today requires two keys to authenticate and decrypt an encrypted email. It also requires coordination between the sender and recipient beforehand. This simply doesn’t translate well to modern business environments where the pace of communication is rapid and the list of recipients is diverse.

An encryption platform like Trustifi offers a way to streamline the process of sending and receiving encrypted emails. With Trustifi, only the sender needs to have Trustifi installed. In order to open an encrypted email sent with Trustifi, the recipient must complete a 2-factor authentication process.


If you are interested in using seamless end-to-end encryption for your business, please contact Trustifi today.


  1. Orman, Hilarie. “Introduction: What Is Secure Email?” In Encrypted Email: The History and Technology of Message Privacy, edited by Hilarie Orman, 1–7. Cham: Springer International Publishing, 2015.
  2. Orman, Hilarie. “How Does Secure Email Work?” In Encrypted Email: The History and Technology of Message Privacy, edited by Hilarie Orman, 33–57. Cham: Springer International Publishing, 2015.

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