How to Encrypt Email: Step by Step Guide

Email encryption is a crucial tool in the fight against email hackers. It helps you to keep sensitive information, data, and documents from being accessed by unwanted third parties. Depending on the type of email encryption used, it can also protect your communications from being accessed by email providers who may use the information in your mail for marketing purposes.


Learning how to encrypt messages and attachments is an important skill to have in a world where data security is a growing concern and privacy is increasingly important to Internet users. Here, we take a look at exactly how email encryption works and how to encrypt your email so you can bring increased security to all of your communications.


What is Email Encryption?


Email encryption is the process of jumbling up the data (encrypting) contained within an email to make it inaccessible to anyone who doesn’t have the means to reassemble the data (decrypting) in its original form. Encryption and decryption are achieved through the use of PKI (Public Key Infrastructure), and anyone using encryption is assigned both a public and private key in the form of a digital code. The use of these keys means that only the two corresponding parties can access information, data, and documents attached to encrypted emails.


 How Does Email Encryption Work?


Email encryption works by allowing two parties access to the keys. This access can be automatically built into email software or managed manually. Either way, email encryption follows the same steps, relying on both the public key and the private key in the following ways in order to effectively encrypt email:


Public Key – The public key is stored on a key server and assigned to your name. This key can be accessed by anyone and is used to encrypt emails. For instance, if someone wanted to send you an encrypted email, they would use your public key to encrypt or digitally sign it.


Private Key – The private key is stored safely away from the public and only you can access it. This key is used to decrypt the email once you have received it. Your private key is what allows you to reassemble the data in its original form.


Despite the fact that all email encryption is based loosely on the public and private key, there are, however, different types of email encryption which work in slightly different ways. Both also offer their own pros and cons when it comes to your communications. The two main types of email encryption protocol are:




This protocol is built directly into some email apps and software. It works from a centralized authority that generates key codes automatically for you. S/MIME provides encryption between you and your recipient, however, the potential still exists for your email provider to access your data.




This protocol requires third-party apps that support end-to-end encryption. It is completely decentralized meaning that ONLY you and your recipient can access the data. However, you must generate and manage your own keycodes, making it less convenient than S/MIME. 


Why is Email Encryption Important?


Anyone considering the reasons why email encryption is important only needs to take a look at some of the high-profile data breaches over the past few years. Today, even the most technologically advanced companies can suffer data loss at the hands of hackers and tech-savvy competitors. This can be expensive, time-consuming, and ultimately destructive, as anyone accessing information on clients, customers, or even colleagues can use it for a range of fraudulent activities including identity theft and webcam hijacking.


For individuals, companies, and other organizations, ensuring your emails and attachments are secured against these threats through the use of email encryption is the best way to stay safe. It offers quick and easy protection for all types of data and, in most cases, it is almost impossible for hackers to break into an encrypted email.


 How to Send Encrypted Email


Sending encrypted messages and learning how to open encrypted email is important if you wish to use this type of security feature. Additionally, it is important to remember that many email providers require both users to have the encryption feature turned on in order to successfully encrypt and decrypt data. Here we take a look at how to send encrypted email with some of the most popular apps and email software currently available.


How to Encrypt Email – Gmail


Gmail uses S/MIME that is integrated directly into the app. However, encryption only works if both parties enable it in the menus. For users asking how to send a secure email with Google, then you’ll first need to head to the admin console in order to enable the feature. Once enabled, follow the steps below to send encrypted emails.


  1. Compose your message in the usual way. 
  2. Click on the “lock” icon that is located to the right of the recipient. 
  3. Click on “view details”. This will allow you to edit the S/MIME settings and level of encryption. 


In the encryption settings, the following colors denote the encryption level you are currently using.


  Green – Your data and attachments are protected by S/MIME encryption. Accessing email content is only possible with a private key.


Grey – Your data and attachments are protected with TLS (Transport Layer Security). Both parties need TLC capabilities in order for your email to remain secure.


Red – Your data and attachments have no encryption security.


How to Encrypt Email – Outlook


The S/MIME protocol is also compatible with Microsoft Outlook, however, it requires additional setup and administration.


  1. Get a digital ID from your organization’s administrator. 
  2. Install the S/MIME control. 
  3. Go to the Gear menu and select “digitally encrypt” or “digitally sign”. 
  4. If you wish to add or remove encryption for individual messages, select or deselect “encrypt this message” in the Message Options menu. 


How to Encrypt Email – iOS Devices


iOS includes S/MIME email encryption built directly into the device. You can change your settings to encrypt all messages by default. 


  1. Go to Passwords & Accounts and select the email account you want to secure. 
  2. Tap on the account and go to Advanced settings. 
  3. At the bottom of the page, the S/MIME settings allow you to sign or encrypt email by default. 
  4. When you compose a message, the lock icon will appear next to the recipient’s name. Click on the lock to “close” it and encrypt your email.


How to Encrypt Email – Other Providers


Other email providers who do not provide encryption features still offer options for users to encrypt email with third-party apps. Below is a list of other services and providers who support email encryption through the use of additional software: 


  •       Yahoo – Uses SSL for security but requires a third-party app for S/MIME and PGP/MIME encryption. 
  •       AOL – Uses third-party apps for PGP/MIME encryption. 
  •       Android Devices – Uses a third-party app for S/MIME or PGP/MIME encryption. 


Here at Spike, we’ve balanced security, speed, and convenience to bring you a secure email app. Read more about it on the Spike website and discover how you can keep your data safe without compromising your workflow.


Additionally, for more inspiration and advice on everything from email security to successful interview techniques, check out the Spike Blog.