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Email Encryption

What is email encryption?

Email encryption is the process of disguising email content into unreadable gibberish, using various encryption techniques to prevent the content from being read by unauthorized users/spammers. It is recommended that you use encrypted email services for your business to ensure secure email communication within the organization and with your customers.

Why is email encryption important?

Emails are the widely used communication medium across businesses. However, they are also risky due to network/ operating system/ process and human vulnerabilities. Emails often contain sensitive organization data and/or personally identifiable information. Hackers/ Spammers can gain access to your data due to one of these vulnerabilities and is a critical threat if the data is not encrypted. Hence email encryption is crucial when sending data through email.

Advantages of email encryption

While emails are a boost to businesses across industries, they also possess a great risk if data security is not taken care of. Email encryption helps organizations to ensure utmost data security. Below are a few advantages of email encryption:

Privacy and Security

Encryption ensures that your data is not compromised right from the moment it is sent till it is received. End-to-end email encryption prevents data theft even when at rest. Only the recipients who have a private key to decrypt the email will be able to read the message.


Both symmetric and asymmetric encryptions require a key to decrypt the email before it can be read by a user. This authentication process does not allow unauthorized personnel to view your sensitive information.

Regulatory compliance

Owing to the obvious threats/risks that exist in today's world, most regulatory authorities like HIPAA, GDPR, etc. demand data to be encrypted. Due to this, most email providers support different email encryption techniques.

How does email encryption work?

Email encryption scrambles the contents of the original message in such a way that it can be read only by the intended recipients. The email encryption process uses computerized algorithms to convert email content into an unreadable format. Those users who have the appropriate key to decrypt the message will be able to read the email.

What are the types of email encryption?

Emails can be secured either through symmetric or asymmetric encryption. Asymmetric encryption is considered the best way to secure your email communication. It utilises a public key to encrypt the message and requires a private key to decrypt.

There are various email encryption methods with which one can secure the contents of an email from being read by unauthorized personnel. Below are some of the widely followed email encryption techniques:

  • Secure Sockets Layer (SSL)
  • Transport Layer Security (TLS)
  • Pretty Good Privacy (PGP)
  • Secure/Multipurpose Internet Mail Extensions (S/MIME)
Encryption protocolDescription


The SSL protocol was launched by Netscape in 1995. SSL uses certificates to authenticate and encrypt email content.


The first version of TLS was introduced in 1999 by Internet Engineering Task Force (IETF). TLS version 1.0 is simply SSL version 3.1. Since Netscape was not associated with IETF, the protocol was given a new name (TLS). TLS encrypts emails between web applications and servers. It can also be used to encrypt emails to maintain data privacy.


PGP uses keys to encrypt and decrypt email messages. It is the first open-source public cryptographic encryption solution.


S/MIME uses digital signatures to authenticate/encrypt email communications. However, there are dedicated Certificate Authorities (CA) from whom one can purchase the digital signature.

Best practices for email encryption

  • Encrypt all your emails (irrespective of whether sent or received).
  • Check with your email service provider and ensure you choose the email encryption method that suits best your organization to secure your email communications.
  • Validate the email encryption indicators when you send or receive an email.
  • The email encryption process is only to prevent unauthorized access to spammers/eavesdroppers. Users must be cautious with the email content and the attachments (if any). Constantly educate your organization's users to follow best practices while viewing email attachments or clicking a URL inside an email to prevent data theft.