Email encryption is the encrypting or disguising of email content to protect it from being intercepted. It is key to outbound email security.
Encryption is often coupled with identity authentication in secure email solutions to make sure email contents can't be read by the wrong people.
Email encryption is a security technique that involves encoding the contents of an email message.
Encryption essentially scrambles the message so that it is unreadable without the correct decryption key.
A decryption key can be permanently held or accessed by proving your identity through recipient authentication.
There are various encryption algorithms of differing strengths that can be used to secure emails depending on their sensitivity.
Anyone transmitting sensitive information by email should use email encryption.
This is crucial for preventing data breaches, identity theft, and cyber attacks.
Encryption is particularly important for businesses and professionals who regularly handle high volumes of sensitive data.
In many cases, encrypting customer data during digital transmission is not just a safety measure but a legal requirement.
Learn how to send secure business emails.
Email has been around as long as the internet has, and it was never designed to be highly secure.
When you send an email, just like with any other data on the internet, it travels through multiple nodes in a network.
At any one of these points, a bad actor could be present. It could be at your mail server, your recipient's, or in between.
If your email contents are not encrypted, they can be accessed, even manipulated, on their journey.
Learn what a cyber criminal could do with your data.
Sensitive information, like personally identifiable information or confidential documents, must always be encrypted.
This includes names, addresses, and birthdays, as well as passwords, banking data, business contracts, and proprietary information.
The risk isn't limited to external communications; internal emails within an organisation or on the same network are equally vulnerable.
In many cases, neglecting encryption can lead not only to data breaches but also to regulatory fines and reputation damage.
Learn about personally identifiable information.
Email encryption transforms readable content into a secure format, making it unreadable to unauthorised individuals.
This process ensures that even if an email is intercepted, its contents remain unreadable to anyone except the intended recipient.
How can you make sure the right emails are encrypted? Here are some email encryption best practices.
Encrypting emails can range from manually encrypting individual messages to rule-based encryption based on the inclusion of different types of sensitive information.
Bulk, automated encryption for the delivery of information to recipients at scale might be necessary for some businesses.
You should ensure that the way you are able to initiate the encryption process matches how sensitive data is being sent.
Outlook users can encrypt emails natively, but this encryption is not suitable for most types of sensitive data.
Dedicated business solutions, like Mailock secure email, can provide additional features for exchanging sensitive messages.
If you're looking for a tool to protect emails to customers, it is especially important you choose a solution that works for them too.
Read our guide to the best secure email services.
It's not enough simply to encrypt sensitive emails - this still leaves them vulnerable to the leading cause of data leaks, human error.
To prevent sensitive emails from being sent to the wrong people, you should combine email encryption with recipient authentication.
This ensures that even if an email is sent to the wrong address, unauthorised persons cannot access it.
Learn more about email recipient authentication.
The most common email clients including Outlook, Gmail, and iOS provide a level of basic encryption:
A key difference between the S/MIME encryption standard and the encryption available with MPME is compatibility.
Whereas the encryption offered as standard by providers requires the recipient's email client to be S/MIME compatible, MPME is more reliable, protecting emails regardless of a recipient's email provider.
"The rights management (MPME) feature is intended as a tool to prevent accidental misuse and is not a security boundary."
It must be noted that MPME's encryption strength is designed for prevention and not security and it is not suitable for the delivery of information to customers in high volumes due to rate limits.
For email encryption to protect sensitive enterprise customer communications, a dedicated secure email service is required.
Learn more about secure email services for businesses.
It's clear that the native email encryption provided by most email clients isn't designed to support customer communications at scale.
This is partly due to volume and their level of security, but it's also important to consider how your recipients will respond.
Are you sending documents to be filled in and returned?
The encryption offered by most email clients (S/MIME) protects email contents and attachments on delivery only.
If a business is communicating with its customers, its the business' responsibility to ensure two-way security.
Secure email solutions don't just offer added security, they enable recipients to easily reply with the same level of protection.
Learn more about secure email solutions and their features.
The latest email encryption statistics, from the most reliable sources.
Emails sent to the wrong person are the #1 cause of reported data breaches in the UK, according to the UK Information Commissioner's Office (ICO).
A 2017 study conducted by researchers from the University of Michigan and California found that between 4% and 10% of internet traffic is intercepted.
An estimated 361.6 billion emails are sent and received each day according to research provided by Statista.
The average office worker sends 40 emails a day and receives 121 emails a day according to research vetted by The Guardian.
Over 1/4 of UK adults have accidentally shared personal data via email with the wrong recipient according to our research.
CSO Online reports that 46% of businesses that suffer from a data breach see negative repercussions affecting reputation and brand value.
Email encryption is a vital component of digital security, transforming sensitive information to prevent unauthorised access.
With various encryption types like TLS, S/MIME, and AES-256, users can choose the appropriate level of security for their needs.
Combining encryption with authentication further enhances protection for customer communications.
While email clients offer basic encryption, specialised solutions are recommended for enterprise use.
Understanding and implementing these practices is key in safeguarding communications against cyber threats and maintaining privacy.
The security impact of HTTPS interception, University of Michigan, California, 2017.
Daily number of e-mails worldwide, Statista, 2024.
UK consumer report email security, Beyond Encryption, 2024.
Does a data breach really affect your firm's reputation?, CSO Online, 2024.
Sabrina McClune, 18.06.24
Sam Kendall, 18.06.24