Keep Your Inbox Confidential: How to Encrypt Your Emails?


Are you concerned about the potential risks of sending sensitive information through email? You're not alone. 


Cyberattacks can occur at any time, and unprotected emails are a common target. But fear not! By implementing end-to-end encryption, you can keep your emails safe from prying eyes. 


In this guide, we'll delve into the inner workings of email encryption, the importance of protecting your email data, and step-by-step instructions on how to encrypt your emails in various email clients.

What is Email Encryption? 

Email encryption is a process used to protect emails that contain sensitive information. It encrypts the email into a coded message that only the intended recipients can decode. It’s like a modern-day wax seal.

How does Email Encryption Work? 

Email encryption transforms an email’s plain text into a coded message with an encryption key. The key consists of a string of characters that make the message impossible to read or decrypt without possessing the exact same key. 


There are two types of email encryption: symmetric and asymmetric. Symmetric encryption uses the same private key for encryption and decryption, while asymmetric encryption utilizes a private key for decryption and a public key for encryption.

Why is Email Encryption Important? 

If you want to protect your emails from cyber attacks, email encryption is your safest bet, especially in remote and hybrid work environments. It keeps your emails obscured until they reach the authorized recipient(s). 


With email encryption, malicious third parties won’t be able to read the email while it’s in transit. It’s essential for protecting sensitive data, such as:

  • Financial data
  • Login credentials
  • Personal information
  • Product data

Types of Email Encryption

There are two common types of email encryption: S/MIME (Secure/Multipurpose Internet Mail Extensions) and PGP/MIME (Pretty Good Privacy/Multipurpose Internet Mail Extensions).


Businesses that rely on private mail servers utilize the S/MIME encryption protocol to encrypt and sign emails with a S/MIME certificate that can be checked through the Certificate Authority (CA) that provided it. 


On the other hand, PGP/MIME is widely used for encrypting personal emails. Here, only the public and private encryption keys are relevant; checking with the CA isn’t a requirement.

Email Encryption Protocols

There are multiple email encryption protocols currently in use. These include:


An open standard that uses symmetric and asymmetric encryption for end-to-end email encryption. 


Secures email messages in corporate environments with asymmetric encryption.


A protocol that keeps email transmissions secure. It’s also used with other protocols to achieve end-to-end encryption.


This protocol is the same as OpenPGP, with the exception that it’s not an open standard.


This is considered an open-source alternative to OpenPGP for email encryption.

How to Open an Encrypted Email?

Here’s how to view a protected email:

  1. Open your email client or app.
  2. Locate the encrypted email in your inbox and open it.
  3. You’ll be prompted to enter a one-time passcode (delivered to your email or via an SMS message).
  4. If the email is successfully decrypted, you should be able to read it just like any other email.

How to Encrypt an Email in Gmail?

To encrypt emails in Gmail, follow these steps:

  1. Open Gmail.
  2. Set up a new email message draft by clicking Compose.
  3. Select “Confidential Mode” at the bottom of your message.
  4. Choose “SMS Passcode” and click Save.

How to Encrypt Email with iCloud Mail?

Here’s how you can protect your emails in iCloud Mail:

  1. Open iCloud Mail.
  2. Navigate to Preferences.
  3. From the "Accounts" tab, choose iCloud account.
  4. Click Advanced.
  5. Under S/MIME, turn on “Encrypt by default”.

How to Encrypt Emails on iOS?

Follow these steps to encrypt your emails on iPhones and iPads:

  1. Open Settings.
  2. Navigate to Mail.
  3. From your account, Click Advanced.
  4. Turn on “Encrypt by default”.

How to Encrypt an Outlook Email?

To encrypt Outlook emails, do the following:

  1. Open Outlook and go to File.
  2. Choose Options.
  3. Under the "Trust Center" tab, Click "Trust Center Settings”.
  4. From the "Email Security” tab, tick the checkbox next to "Encrypt contents and attachments for outgoing messages”.

How to Open an Encrypted Email in Outlook?

If you receive an encrypted email in Outlook, you should be able to open and read it just like any other message.


However, if you don’t have a Microsoft 365 subscription or are using a different email client like Gmail or Yahoo, a one-time passcode or a special sign-in procedure might be required.

In Outlook, follow these steps: 

  1. Select Read the message.
  2. Choose your sign-in method.
  3. Sign in with a one-time passcode or use your Google, Yahoo, or Microsoft account.
  4. Enter your sign-in credentials or the one-time passcode sent to you to view the email.

How to Encrypt an Email in Outlook 365?

To protect Outlook 365 emails, follow these steps: 

  1. Open Outlook 365.
  2. Create a new email draft.
  3. Under file, select Properties.
  4. From security settings, tick the “Encrypt message contents and attachments” checkbox”.

If you want to encrypt a single message, here’s what you can do:

  1. Open Outlook 365
  2. Create an email draft
  3. Under the options tab, click Encrypt
  4. Choose Encrypt only from the drop-down menu

How to Encrypt a Yahoo Email?

To Encrypt emails on Yahoo Mail, you need to download and install a third-party email encryption service. 

How to Encrypt an Email in Outlook Web App?

To encrypt email in the Outlook web app, do this:

  1. Create a new message and tap on “more options”.
  2. Click Message Options.
  3. Select “Encrypt this message”.

Encrypting Emails With Android

On Android devices, emails aren’t encrypted by default and there’s no native encryption option. However, you can install a third-party app to encrypt email with S/MIME or PGP/MIME.

Encrypting Emails With AOL

Similar to email encryption on Android, you need to set up a third-party tool to encrypt email with AOL. Downloading the PGP implementation before proceeding with the encryption steps is necessary. 

Which Email Providers Require Third-Party Support?

Not all email providers have native encryption functionality. The following email providers require an extra step to enable email encryption:

  • Yahoo
  • Android
  • AOL

Email Encryption Services

Some of the most popular email encryption services include:


A free email encryption app that works with android devices. It supports OpenPGP, S/MIME, TLS, and PDF. 


Compatible with PGP. Works on both iOS and Android smartphones and tablets. There are free and paid plans(starting at $9.99/month).


End-to-end email encryption that works with Hotmail, Yahoo, Gmail, and Outlook. It has free and paid plans (starting at $87/month).


A free webmail encryption service that supports OpenPGP encryption on GMX, Gmail, Outlook, Posteo, Yahoo, and WEB.DE. 

What Else Can I Do to Keep My Emails Safe?

Other than encrypting your emails, here are a few additional tips to keep your messages protected:

  • Use Multi-Factor Authentication (MFA).
  • Train your employees on how to avoid phishing emails.
  • Use a strong password.
  • Change your password periodically.
  • Scan attachments before opening them.
  • Avoid using public Wi-Fi to access emails.

Protect Yourself Online with CyberTalents

Read more articles on CyberTalents blog to learn how to protect yourself online and avoid cybersecurity threats:

Work From Home Cybersecurity, Tips, and Risks

Types of Cybersecurity Threats, and How to avoid them?

What is Cybercrime? Types, Examples, and Prevention

What are the Different Types of Encryption? List you must Know