Learn How to Encrypt Your Emails

Do you want to protect your outgoing emails to ensure better privacy? Learn how to encrypt your emails and keep your data safe.
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If you’ve ever needed to send sensitive information by email, you probably want a way to secure that data.

Sending out messages with private information can leave you vulnerable to a hacker, who can hijack your email communications. Without email encryption, your messages are open to being compromised by third parties along the way.

The good news is that there is a way to communicate safely by email and not worry that your data will get stolen. Since email is such a popular way to share information, you want to lock it down so that the intended recipient is the only one who sees it.

Keep reading our guide on how to use encryption for increased email security to help ensure your data stays safe.

In this article
What does encrypting email do?
How to encrypt email in Outlook
How to send a secure email in Gmail
How to send a secure email in Yahoo Mail
How to scan your email for viruses
Bottom line

What does encrypting email do?

The goal of email encryption is to keep unauthorized users out of your sensitive data communications. That can happen whether your email gets intercepted by a hacker or if you accidentally send the email to the wrong person.

Email encryption is an essential tool to prevent data breaches. The process works by scrambling the message into an unreadable format. It converts the plain text into undecipherable text that can only be read by the recipient who has a private key to decode the message.

Basic email encryption happens when the message is sent, but the data gets stored in clear text. This process makes the content readable by the writer of the email. With end-to-end encryption, your email is encrypted even before you hit Send so it can’t be read by your email server or anyone without an encryption key.

Encryption helps to ensure communication security and provides a way for the sender and intended recipient to be the only one who can read the email.

Types of email encryption

There are two primary types of email encryption, S/MIME, and PGP. Those stand for Secure Multipurpose Internet Mail Extension and Pretty Good Privacy.

S/MIME is built into most modern email software and requires you to get keys from a specific Certificate Authority. This encryption type is an Internet Engineering Task Force (IETF) standard that delivers digital signatures and public key encryption. When you digitally sign your emails, it verifies you as the valid sender of the message, which helps guard against phishing attacks.

PGP encrypts and decrypts your email messages using file encryption methods and digital signatures. PGP was one of the first free public key cryptography options. Today PGP gets used to defend businesses and individuals, as it provides secure online communication, including text messaging.

The differences between these two encryption options are primarily due to their design. PGP is made for plain texts and can be used for work or personal email accounts. It is not as efficient as S/MIME, which is best for organizational use.

While both are excellent ways to encrypt email, PGP or S/MIME might be better in certain situations:

  • Using a VPN: If you want to use a VPN, you’ll need to use PGP because S/MIME is only for email services.
  • Send multimedia files (videos, images): If you need to process multimedia files along with email, S/MIME is the better option, as PGP is not designed to handle anything other than plain texts.
  • Download files: You can download files safely with S/MIME.

PGP is available for free, while you will need to pay to get the S/MIME certificate. S/MIME costs vary but can range from around $13 to $34 per year.

Heads up: Both sender and recipient need an S/MIME certificate

It is also worth noting that if you choose S/MIME encryption, it will only work if both you and the recipient have that service.

How to encrypt email in Outlook

Outlook supports S/MIME and Microsoft 365 Message Encryption. The latter only works if the sender has the Office 365 Enterprise ED3 license, so we’ll focus on S/MIME encryption here.

When you want to set up S/MIME encryption in Outlook, you can do so with a few simple steps. Remember, to use this service, you and the recipient must have an email app that supports this protocol. First, you have to add the certificate to the keychain on your computer.

When you place an order for the S/MIME certificate, you will get an email with a link to open it. Once you click the link, you’ll enter the password you used when buying the certificate. Now follow the steps below to install the S/MIME certificate.

  1. Open your Outlook email client and go to Options, then open the Trust Center and choose Trust Center Settings.
  2. Choose Email Security. Under the Encrypted email section, choose Settings.
  3. Look for Certificates and Algorithms, then click Choose and select your email certificate, then click OK.

Now that you have added your certificate, you can encrypt your emails in Outlook. Open your Outlook application and follow the steps below.

How to encrypt a single email message in Outlook

  1. With the message you want to encrypt open, go to File then Properties.
  2. Choose the Security Settings option.
  3. Check the box next to Encrypt message contents and attachments.
  4. Hit Send when you’re done writing your email.

How to encrypt all Outlook emails

  1. Go to File, then Options > Trust Center > Trust Center Settings.
  2. Open the Email Security tab and look for the Encrypted email section.
  3. Check the box next to Encrypt contents and attachments for outgoing messages.

How to send a secure email in Gmail

You can set up hosted S/MIME encryption in Gmail if you use a Google Workspace account. The supported editions include; Enterprise, Education Fundamentals, Education Standard, Teaching and Learning Upgrade, and Education Plus.

You can also send a secure email using your personal Gmail account. Use these steps to send confidential messages and protect your personal information in Gmail.

  1. Open your Gmail. Click on Compose to open a new email message.
  2. In the bottom right corner, click on Turn on confidential mode.
  3. Set an expiration date and passcode that limits when and how the recipient can access the text and attachments.
  4. You can choose either No SMS passcode or SMS passcode. The recipient will either bypass a code option or have to enter one in before accessing the email.
  5. Click Save.

Gmail encryption level colors

Gmail uses colored lock icons to let you see the level of encryption for a message. That color will change according to the security level. The colors you will see are green, gray, and red.

  • Green means that S/MIME encryption has been used. This is suitable for your most sensitive data.
  • Gray is the standard encryption level (TLS). This option is okay for most messages. The Transport Layer Security (TLS) gets used by other email services that don’t support S/MIME.
  • Red means that no encryption is used. The email is not secure and past messages sent to the recipient's domain will be used to predict the security of future emails.

How to send a secure email in Yahoo Mail

If you want to send a secure email from Yahoo, you need to know that the email service doesn’t use an encryption protocol for end-to-end protection. When you want to use encryption, you must use a third-party application.

To encrypt your Yahoo email, download a third-party plugin. For this example, we'll use the Mailvelope app. You can also use other third-party encryption plugins, like ProtonMail or PreVeil.

To start sending encrypted email messages with Mailvelope, open your Yahoo Mail.

  1. Open a new message in Yahoo.
  2. Click the Mailvelope icon in the top-right corner of your message window.
  3. Write a message, then click Encrypt.
  4. Send the message.

Most third-party plugins will work similarly to this example.

How to scan your email for viruses

When you want to have secure email communication, you can also use antivirus software. That will ensure you are doing everything possible to protect your data. Good antivirus software, like Norton or AVG, is easy to use and will scan your email for viruses.

Some email providers, like Gmail, also automatically scan all incoming and outgoing emails for viruses. Gmail in particular says it will reject any message that includes an attachment infected with a virus, or it will prevent you from downloading the infected attachment.



Can you encrypt email by typing “encrypt”?

Typing “encrypt” in your subject line does not ensure the message will be encrypted. Some vendors support using the trigger word “secure” as a keyword for a higher level of encryption. You should always check with the vendor to know if their service supports trigger words.


How can I encrypt an email for free?

If you want to encrypt an email for free, you can use a third-party application. You can choose a service that gets audited by other third parties for security. Two of these options are Proton Mail and Thunderbird.


Is it safe to send your SSN over Gmail?

It's only safe to send your Social Security number (SSN) over Gmail if it is encrypted. If you cannot be certain that it will be encrypted, you should not send your SSN over Gmail.

Bottom line

Most of us have sent checks in the mail, and we’ve tried to hide the fact that money is in the envelope. We might also hide the key to our home under a plant or other item outside. If we go to this much trouble to keep these items secure, why would we take chances with our most sensitive data?

When you encrypt your email, you are keeping your personal information private from everyone except the intended recipient. That means you can encrypt messages containing your credit card, healthcare information, and other sensitive data.

You can use the steps we’ve discussed to secure your emails and keep your information private. It is also crucial that you scan your email for viruses because it can prevent problems with malware invading your communications. You don’t want to unknowingly forward a virus through email to someone else. If you’re still on the fence, you can read more about why antivirus software is necessary and learn how to give yourself the best online protection possible.

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Author Details
Patti Croft is a seasoned writer specializing in technology, with three years of experience. With a B.S. in Computer Science and a background as a technical analyst and security specialist, she covers a range of topics like data security and parental control software.