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.

Male professional sending secure emails to his clients on laptop using mailock

Outlook send & receive

How it works

1. Send

Start a secure email with the Mailock Outlook add-in, choosing from a range of authentication challenges.

Mailock secure email button on the Outlook ribbon using add-in

2. Receive

Recipients receive a notification in their inbox and must pass your authentication challenge to unlock the message.

Enter the code to unlock your secure email in the Mailock Outlook add-in

3. Reply

Replying is easy - recipients can use Mailock for desktop or web to keep sensitive messages and files secure.

Secure read pane in Mailock web app after receiving a secure email in Outlook
Mailock secure email button on the Outlook ribbon using add-in
Enter the code to unlock your secure email in the Mailock Outlook add-in
Secure read pane in Mailock web app after receiving a secure email in Outlook


Check recipient

identity for access

Set authentication challenges

Ask your recipients to prove they 'are who they say'. Set authentication challenges for outbound emails 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.
Email recipient authentication challenges on smartphone for message sent in Outlook

Trigger words

Stop email mistakes

before it's too late

Get sensitive data alerts

Customise a preset list of words that trigger ‘sensitive data’ alerts. Encrypt an Outlook message before it sends with a single click. Just install the secure email add-in.

Trigger word warning in Outlook using the Mailock add-in

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.

Professional male in office using the Mailock Outlook add-in revoke function

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 also 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's 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 Outlook email encryption usage and savings


The best Outlook add-in for email risk

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

Email icon


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


Deliver emails and attachments with end-to-end AES-256 encryption - virtually impenetrable protection for sensitive data.

Message read icon


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

Lightbulb icon


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.
Stars icon


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


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


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


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

Paragon Logo
Aegon Logo
Royal London logo
Origo logo
Equiniti EQ Logo
abrdn logo
Man at office desk recalling an email in outlook successfully

Blog post

How To Recall An Email In Outlook

Sending an email in error is easy, but recalling it in Outlook can be tricky.

Contend Feed

  Latest Outlook posts

10 min read
Man encrypting email in his kitchen using laptop.png
14 02 24

How To Encrypt Email Attachments (Outlook, Gmail, & iOS)

Learn how to encrypt email attachments in Outlook, Gmail, and iOS to protect your sensitive information and reduce the risk of data breaches.

4 min read
woman with glasses using laptop to hide her calendar in office 365
12 06 23

How To Hide Your Calendar From Everyone In Office 365

The Office 365 calendar is a useful tool, but you don't always want everyone to see your appointments. Here's how to hide your calendar in Office 365.

3 min read
woman encrypting an email in outlook
02 06 23

How To Encrypt An Email In Outlook

Encrypting your emails can help to protect your privacy and security by reducing the chance of interception. Here's how to encrypt an email in Outlook.


FAQs, answered

What is Mailock for Outlook?

Mailock for Outlook is an email encryption add-in that allows you to secure your emails and authenticate recipients directly within your Outlook client on Windows.

How does Mailock ensure the security of my emails?

Mailock encrypts your emails and attachments with end-to-end encryption, ensuring that only the intended recipient can access the content. It also provides authentication challenges to verify the recipient's identity.

Can recipients reply securely to my encrypted emails?

Yes, recipients can reply securely using Mailock, even if they don't have a Mailock account. They can read and respond to your secure messages without any additional cost.

How do I revoke a sent email using Mailock?

If you need to revoke an email sent in error, Mailock allows you to do so even if the recipient has already opened it. This helps in containing potential data breaches.

What are trigger words and how do they work?

Trigger words are customisable keywords that, when detected in your email, prompt you to encrypt the message before sending. This feature helps prevent accidental exposure of sensitive information.

Is Mailock compliant with data protection regulations?

Yes, Mailock helps you comply with data protection regulations such as GDPR by encrypting personal information and providing audit trails for email interactions.