Mailock® For Outlook

Secure your

Outlook emails

The email encryption Outlook add-in

Encrypt Outlook emails and set recipient authentication challenges with our email encryption add-in for Windows.

man sending secure emails to his clients using mailock

Outlook secure send

How it works

1. Encrypt

Click the ‘Secure Email’ button in Outlook, compose your message, and hit ‘send’. Set a challenge so only the right people gain access.

Mailock button on the Outlook ribbon

2. Connect

Recipients click ‘Open’ on the notification delivered to their inbox. They’ll answer your challenge, or if they're trusted, they can read right away.

Enter the code to unlock your secure email

3. Engage

If recipients need to respond to a secure message, they can use Mailock to compose, attach, and reply using their existing email address and account.

Secure read pane in Mailock web app
Mailock button on the Outlook ribbon
Enter the code to unlock your secure email
Secure read pane in Mailock web app

Outbound security

Extend Outlook for

outbound security

Prevent interception and fraud

Protect confidential information with an email encryption Outlook add-in to cover you against outbound email risk.

  • Multi-factor authentication
  • 'Before you send' trigger alerts
  • Full message and attachment revoke

    (regardless of receiving email client)
Extend Outlook for outbound security


Check recipient

identity for access

Set authentication challenges

Ask your recipients to prove they 'are who they say they are' to gain access to sensitive emails you send them in Outlook.

  • SMS: Send a one-time code to your recipient's mobile device.
  • Q&A: Ask your recipient a question only they could correctly answer.
  • Unipass ID: Allow financial professionals to verify their ID using Unipass.
Man receiving recipient authenticated email-1

Trigger words

Stop email mistakes

before it's too late

Get sensitive data alerts

Customise our preset list of trigger words that surface a ‘sensitive data’ alert if present in an email. Click a button to secure an Outlook message before it sends.

Trigger words in outlook

Message revoke

Revoke you

can rely on

Lock down emails sent in error

Outlook's native email recall works in a limited few scenarios. Mailock gives you the power to revoke secure messages unilaterally to contain a data breach.

Man in office looking at laptop stressed about sending email to the wrong person

Outlook email compliance

Fulfil your obligations

Encrypt personal information (GDPR)

The Information Commissioner's Office (ICO) and Financial Conduct Authority (FCA) require businesses to encrypt sensitive data transferred digitally. The ICO can levy fines of up to £17m for non-compliance (or 4% of turnover).

Record proof-of-delivery (MIFID II)

All businesses should record digital communications and retain proof-of-delivery to align with ICO guidance. Proof-of-receipt is required by the FCA for certain types of document (e.g., KIDs).

Protect customers (Consumer Duty)

Are you encouraging customers to send their information into your business unsecured? The FCA Consumer Duty is a mandate to provide easy-to-understand communications and protect customers from financial harm.


We can send and receive our client information safely. That's important.

Mailock removes a lot of the risk and GDPR concern around dealing with everyone’s favourite communication method - email.

 Rob Hastings  Harwell Finance
Wealth planning meeting to discuss email encryption usage and savings (1)


The best Outlook add-in for email risk

Encrypt confidential emails and authenticate recipients with our secure email encryption add-in for Windows Outlook.



Send secure emails from Windows Outlook. Click the Mailock icon to compose an encrypted email and set your recipient authentication.


Deliver emails and attachments with end-to-end encryption - the NSA standard for classified data. Don't leave your data open to risk.



Select from a range of authentication methods. Set SMS or question-and-answer challenges to make sure the right people gain access.



Catch sensitive emails before it's too late, with custom trigger words. If they're included in a message, you'll be alerted to send it securely.


Recipients reply securely for free. They'll also get some free sends. Empower clients with an encrypted thread to your business.


Record audit trails for every message interaction including opens, downloads, and revoke calls. Get read notifications so you can follow up.


Revoke secure emails even if they've been opened, regardless of whether your recipient is using Outlook, Gmail, or another provider.


Double-click any Outlook message that was secured with Mailock and it will automatically be decrypted to your inbox for easy access.

Download the Outlook
Add-In Data Sheet

Woman speaking on Teams call with colleague using laptop in office

Blog post

The Best Outlook Add-ins You Didn't Know You Needed

Microsoft Outlook can be made pretty powerful with some add-ins. We break down the best Outlook add-ins for productivity, security, and collaboration.

Case studies

  Hear from our users

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Boosting Security And Engagement At Rapport Financial Strategists

This case study shows how Rapport Financial Strategists improved the security and effectiveness of their client communications using Mailock secure email.

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Brearley Law Puts The Protection Of Client Data First With Mailock

According to the most recent ICO statistics, the UK legal industry is responsible for 8% of total data breach incidents reported in the past year.

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Securing client communications at Stonebridge Financial
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Securing Client Communications At Stonebridge Financial

Find out how Stonebridge Financial secured their email communications using Mailock, driving efficiency and engagement with their clients in the process.