How to Send a Secure Email (Encryption Options, Passwords, & MFA)

Worried about sending personal or financial data over email?

You’re right to be cautious - email isn’t secure by default, but it can be.

Whether you're a consumer, financial professional, or IT team, protecting sensitive emails is essential.

Most email services only encrypt data in transit. Once a message lands in someone's inbox, it’s often readable by others with access.

Let’s look at the best ways to send a secure email, how they work, and when to use them - including a step-by-step guide to sending a secure message with recipient identity checks.

Why Secure Email Matters

Every year, thousands of breaches occur due to mis-sent or intercepted emails.

Whether it’s personal ID, bank details, or client information, sending it unprotected could break trust - and the law.

Regulations like the UK GDPR and FCA’s Consumer Duty require businesses to take appropriate steps - including encryption - to secure data in transit.

Even consumers are encouraged to take precautions when sending documents like passports or payslips.

Email is convenient, but without encryption, it’s like posting a letter without an envelope.

Ways to Send a Secure Email

1. Use an Encrypted Email Platform

Secure email platforms like Mailock offer end-to-end encryption combined with advanced features to protect against risky email mistakes.

Only the sender and intended recipient can open the message. Add recipient authentication, and it becomes a sealed vault.

• Email and attachments are encrypted at rest and in transit
• Verify the recipient (e.g. SMS code, security question)
• Revoke or track email access

Best for: financial services, customer communications, regulated data.

2. Rely on TLS (Transport Layer Security)

Most modern email providers encrypt messages in transit using TLS. This protects against interception between mail servers, but not at rest in the inbox.

• No setup needed - works automatically with most providers
• Stops eavesdropping in transit
• Compatibility issues can lead to breaches if not setup correctly
• Doesn’t prevent access once delivered

Best for: day-to-day, low-sensitivity communications.

3. Send a Password-Protected File

Encrypt the file (e.g. PDF or Word doc) with a password before attaching it to an email. Share the password separately - never in the same message.

• Quick workaround if you lack a secure email tool
• Limited to the attachment, not the email itself
• Often leads to compatibility problems for recipients
• Risky if passwords are weak or shared insecurely

Best for: one-off personal use with trusted recipients.

4. Use PGP or S/MIME

Built-in encryption standards for advanced users. These protect email content using digital certificates or keys, but require manual setup.

• Strong end-to-end encryption
• Often used in corporate or government settings
• Tricky to configure and not ideal for casual users
• Must be combined with recipient authentication to protect against the most common data leaks - emails sent to the wrong people

Best for: experienced users or managed IT environments.

How To Send a Secure Email With Mailock

Mailock makes encrypted email simple. Here's how it works:

1. Write your message: Compose the email and add attachments in Outlook or using Mailock online.
2. Choose a verification method: Set a challenge question or SMS code.
3. Hit send: The email is encrypted and locked to the recipient’s identity.
4. Recipient opens: They verify themselves to access the secure message and any attachments. They can also securely reply.

"We designed Mailock to make secure communication effortless - encryption and identity checks, built into the tools people already use."

Mike Wakefield, CTO, Beyond Encryption

When Should You Use Secure Email?

If you’re sending:

• Personal data (e.g. passport scans, medical info)
• Financial documents (e.g. tax returns, mortgage details)
• Client records or legally sensitive information

…then encryption is a must. TLS isn’t enough on its own - use a secure email service or encrypt the content directly.

For professionals in financial services and regulated industries, secure email is especially critical.

The FCA expects firms to protect consumers and their data under the Consumer Duty.

Using encrypted, auditable communication tools like Mailock helps demonstrate compliance and safeguard trust.

Tips to Stay Secure

• Double-check recipient addresses
• Use multi-factor authentication on your email accounts
• Never send passwords or sensitive info unprotected
• Ask intermediaries (financial advisers, mortgage advisers, brokers) and providers (banks, insurers) to send you info securely

References

Encryption Scenarios (UK GDPR Guidance), ICO, 2025

Why Password Protect Documents?, Adobe, 2023

Finalised Guidance FG22/5: Consumer Duty - Ensuring Secure Communication, FCA, 2022

Are UK Consumers Not Taking Email Security Seriously? (2023 Research), Beyond Encryption, 2024

Reviewed by

Sam Kendall, 26.06.2025