Secure Email on a Budget: Free Options Compared

Can you protect your email privacy without paying a penny?

With phishing, data breaches, and accidental leaks rising year-on-year, secure email is no longer just for large enterprises.

I've spoken with hundreds of people who assumed email was “secure enough” - until they sent something sensitive to the wrong person or discovered how easily inboxes can be compromised.

If you're looking for a free way to protect sensitive information, there are now several credible options - including Mailock, a secure email tool designed to work with your existing inbox.

Let’s break down what secure email really means, compare the leading free tools on the market, and highlight the key trade-offs.

What Is Secure Email?

Secure email means your message is protected in transit, at rest, and on arrival. That typically involves:

• End-to-end encryption: So only the intended recipient can read the message content.
• Recipient authentication: To make sure the person opening the message is who you intended.

Standard email providers (like Gmail and Outlook) usually only encrypt data in transit.

Once your message reaches the recipient’s inbox - or if it's sent to the wrong person - it’s no longer secure.

That’s a problem. In the UK, over 1 in 5 data breaches are caused by email mistakes such as misdirected messages or incorrect CC usage.

Why Consider a Free Secure Email Service?

Many secure email solutions are designed for enterprise use - and priced that way.

But individuals and sole traders also need to send confidential information - whether it’s financial documents, ID, or personal medical details.

I've heard the same thing from countless advisers and small business owners: “I know I should protect emails, but the options seem too complicated or expensive.”

That’s exactly why we launched our Mailock Free plan.

We believe a free secure email tool should be available to everyone who needs to protect their data, offering:

• Strong encryption at no cost.
• Identity verification to prevent unauthorised access.

But there are a few other options. Different tools suit different people and contexts. Let's compare them:

Free Secure Email Tools Compared

Mailock Free

• Encryption: AES-256 end-to-end encryption.
• Authentication: Q&A or SMS identity challenges.
• Send limit: 5 secure emails/month. Unlimited secure replies.
• Works with: Outlook via add-in or web browser. No need to change your email address.
• Compliance: Designed for GDPR, Consumer Duty, and FCA-regulated communications.

Standout: The only free solution that adds recipient authentication to messages sent from your own email address.

This matters if you want to protect sensitive information without switching inboxes.

ProtonMail Free Plan

• Encryption: PGP-based end-to-end encryption for Proton-to-Proton. External emails require password-protected link.
• Authentication: Shared password manually created by sender.
• Send limit: 150 emails/day. 1 GB storage.
• Works with: Proton webmail or app only. No integration with Gmail, Outlook, etc.
• Extras: Encrypted calendar, VPN (basic), and cloud storage.

Standout: Ideal for users wanting a new, private email account (@proton.me) with added tools.

Tutanota Free Tier

• Encryption: Strong encryption, including subject lines and attachments.
• Authentication: Password entry required by recipient (set by sender).
• Send limit: No specified daily cap. 1 GB compressed storage.
• Works with: Tutanota apps or webmail. No external inbox integration.
• Extras: Encrypted calendar. Fully open source.

Standout: Great for privacy advocates comfortable with technical configuration.

Who Should Use What?

• Mailock Free: Best for users who need to send secure messages from their existing email (e.g. advisers, clients, legal professionals), especially via Windows Outlook. The recipient verification is a key differentiator.
• ProtonMail Free Plan: Best for those wanting a private inbox, built-in calendar, and a new email address.
• Tutanota Free Tier: Best for users prioritising open-source tools and maximum encryption, who are happy to work within a dedicated app.

"We created Mailock Free to make secure email available to anyone, not just big enterprises."

Paul Holland, Founder, Beyond Encryption

FAQs

Is Mailock Free Really Free?

Yes. You can send 5 secure emails per month and receive unlimited secure replies without paying. No credit card required.

What If My Recipient Isn’t Tech-Savvy?

Mailock’s Q&A challenge is easy to complete.

The recipient clicks a link, answers your question, and reads the message securely - no account setup needed.

Which Service Is Most Private?

Tutanota and ProtonMail strip IP addresses and encrypt stored data.

Mailock adds recipient verification and message-level control, which is essential for enterprise regulatory compliance in the UK.

Can I Use These Tools With My Gmail or Outlook Account?

Mailock integrates with Outlook and works alongside any provider using its web interface.

ProtonMail and Tutanota require their own apps or webmail. They don't integrate with external inboxes like Gmail or Outlook.

References

ICO: Cyber Security Breaches Survey, ICO, 2025

Reviewed by

Sam Kendall, 24.07.2025