Man sending secure emails to his customers
4 min

How To Send Secure Confidential Emails To Customers

It goes without saying that maintaining regular interactions with your customers is vital for business. Email remains one of the most powerful tools in a business’s communication, with an estimated 80% of users checking their inboxes every day.

The flexibility and convenience that email offers for can’t be beaten. However, while email use might be substantial, with around 3.4 million emails sent every second, it is not always the most secure method of communication.

Why Do Emails Need To Be Secure?

As a business, you may send and receive sensitive information in emails that could potentially be harmful if it falls into the wrong hands.

This includes data such as the full names, addresses, phone numbers and bank details of your customers.

Businesses are duty-bound to protect personal information

Threat actors with access to this data can use it with malicious intent. For example:

  • Using pre-existing credit or debit card information to purchase items
  • Applying for credit cards or loans in the victim’s name
  • Filing fake tax returns to get an income tax refund
  • Using health insurance to gain access to private medical care
  • Selling private information on the dark web

Source: Experian

For organisations dealing with substantial amounts of data, maintaining customer trust is paramount.

33% of UK businesses that have suffered a breach of data have lost customers. That is why it is vital to ensure that emails are secured against threats.

Why Are Emails Not Considered Secure?

The modern-day email was originally a local fire-sharing system at the Massachusetts Institute of Technology in the 60s, meaning it was never made secure enough for its current-day usage and is lacking several necessary inbuilt security functions.

the history of email

This leaves it vulnerable to cyber-criminal activity, such as…

Phishing: This is when attackers trick users into clicking harmful links that will either direct them to a risky website or download malware and ransomware directly to their devices. This can result in your systems being sabotaged or locked down or your data or money being taken.

Interception: Occurs when threat actors place themselves directly between an individual and a data source or network hub, digitally eavesdropping and collecting any personal information that is revealed, such as usernames and passwords.

Impersonation: Using social manipulation and personalisation, such as utilising email addresses that look like legitimate companies, cybercriminals trick individuals into sending sensitive data.

However, criminal activity is not the only threat you should be aware of. In fact, human error plays a huge part in email safety, with businesses being 61% more likely to send an email containing sensitive data to the wrong recipient than to fall victim to a successful phishing attempt.

How Can You Make Email Secure?

There are several methods through which businesses can secure their emails and protect their customers' sensitive data from cyber threats.

Woman using laptop to encrypt emails


Encryption enables you to hide or disguise the contents of your emails, including any attachments.

The encryption and decryption processes are carried out through the use of ‘keys’ – strings of unique characters that, much like physical keys, ‘lock’ your data from plain sight and prevent unwanted third parties from accessing sensitive information.

Encryption protects against email interception, as threat actors, even if they are monitoring your communications, will be unable to decipher the content. There are different types available to use, however, the best type for you and your customers is end-to-end encryption, as it secures your emails both at rest and in transit.

To find out more about how email encryption works, check out our comprehensive guide.

 Identity Authentication:

Authentication is becoming steadily more commonplace across different organisations and industries, with multi-factor authentication becoming more widespread as the standard for business email protection.

Email authentication works by locking your messages until the reader has identified themselves as the intended recipient. This identification process can take several forms, including:

SMS: Send your customers a text message to their mobiles with a code that they must input to unlock email access.

Q&A: Ask your customers a question whose answer only they will know, which they must input to gain access to the email.

Biometrics: While not as widespread as other methods, customers could use their unique biological characteristics to unlock access to their emails, such as face and fingerprint scans.

ML Pro Mobile Challengess

 Message Revoke:

At one point or another, we have all fallen victim to the accidental email send. We either send a message to the wrong recipient, or we send the wrong attachment to the right recipient.

While authentication can help with the first instance, ensuring that even if an email was sent to the wrong individual, they would be unable to open it, we need a solution for the second situation.

Email revoke is when you block access to an email you have sent, ensuring that any sensitive data contained within does not remain in the wrong recipients’ hands.

ML Outlook Revoke Every Time Min

Currently, something called "recall" is natively available on Outlook. However, it must be noted that this only works in particular situations, and isn’t compatible with all email providers, leaving the possibility of successfully recalling your email rather slim.

For guaranteed revoke, an advanced secure email solution like Mailock, will provide you with a function that can instantly block access.

Secure Email

As each of the above methods protect against a certain type of risk, they work best when combined. Our secure email solution, Mailock, offers all of this, and more:

  • Military-grade, AES-256 encryption
  • Multi-factor authentication
  • Full message revoke
  • Free read and reply for clients
  • Read alerts and audit trails

Further Reading

Deliver sensitive information securely with Mailock


Originally posted on 08 07 22
Last updated on March 14, 2024

Posted by: Sabrina McClune

Sabrina McClune is an expert researcher with an MA in Digital Marketing. She was a finalist in the Women In Tech Awards 2022. Sabrina has worked extensively with B2B technology companies conducting and compiling thorough academically driven research to produce online and offline media. She loves to read fantasy novels and collect special edition books.

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