Skip to main content

Features > Challenge

Recipient authentication for secure email

Help ensure sensitive emails open only for the intended recipient. Add a recipient access check to reduce wrong-recipient risk, without creating unnecessary friction.

Mailock authentication pane with an SMS code entry
HSBC logo
Aegon Logo 2023
Royal London logo
Aviva Logo
Equiniti EQ Logo
abrdn-logo-horiz-white-svg

Inbox delivery to the right people

Mailock® encrypts every sensitive message.

Recipient authentication adds an extra layer of control by requiring an access check before the encrypted content can be opened, helping reduce wrong recipient access.

Add an extra layer of protection with recipient authentication before messages are accessed

Step-by-step

How it works

1. Compose

Send a secure email from Outlook or the Mailock web app, adding attachments if needed.

Mailock secure email screen showing email secure

2. Encrypt

Mailock encrypts the email and attachments. You can send with encryption-only, or add an access check for extra control.

Mailock email notification with branded company message

3. Challenge and access

If a challenge is applied, the recipient must complete it before they can open the encrypted message. If they can't pass the check, access is blocked.

Mailock recipient challenge and read process
Mailock secure email screen showing email secure
Mailock email notification with branded company message
Mailock recipient challenge and read process

Security & Compliance

Stronger access control for sensitive email

Recipient authentication controls who can open encrypted messages using email, SMS, or security-question access checks.

This extra access step helps reduce unauthorised disclosure risk and support expectations from regulators including the ICO and the FCA around protecting sensitive communications.

Help recipients quickly access secure messages, without adding friction to their workflow

Access checks

Ways to authenticate a recipient

Choose the check that suits the recipient and the sensitivity of the message.

SMS verification icon

SMS verification

Mailock can send a one-time code to your recipient’s mobile number, which they enter to open the encrypted email.
Question and answer icon

Question and answer

When you don't have a mobile number, set a custom question only the recipient should know. They have five attempts.
Unipass ID icon

Unipass ID

Financial professionals can sign in with their Unipass ID, the identity they already use across financial services, for trusted low-friction access.
Email verification icon

Email verification

A one-time code can be sent to the recipient’s email address as a lightweight access check.

Identity

Send an identity check by secure email

ID, KYC, and AML checks

An identity check evidences who your client is and returns a results pack to you. Send one by secure email from Outlook or the Mailock web app.

A client completing an identity check on a mobile phone at home
Capterra badge
Software advice badge
GetApp badge

Deployment & fit

Built to fit your processes

Sending a secure email with Mailock Pro

Pro

For professionals and teams

Add recipient access checks to day-to-day secure email, without changing how you communicate.

IT manager reviewing secure email access controls

Enterprise

For high-volume contact

Apply recipient authentication consistently across teams and workflows, including integrated delivery through the Mailock Secure Email Gateway.

Secure email delivery settings for high-volume sending

Automated

For scaled digital delivery

Deliver customer communications at scale with automated secure email delivery, with recipient challenges built into the access experience when required.

10%
of UK adults by Q1 2027
300K+
Users
2.5K+
Companies
80%+
Open rate
Business team looking at laptop and smiling around boardroom table

Plans & pricing

View plans

Take a look at our plans to address your communications security challenges.

Questions?

FAQs

What is recipient authentication in Mailock?

Recipient authentication is an access control for encrypted emails. It uses multi-factor authentication and access checks to help ensure only the intended recipient can open the secure message.

Is recipient authentication always used with encryption?

Yes. Authentication is the step that controls access to the encrypted message. Some organisations use encryption-only delivery for lower-risk messages, and add recipient challenges when they need stronger controls.

Can we apply recipient challenges consistently across teams?

Yes. Many organisations use policy-based rules and security alerts to help ensure the right checks are applied consistently, especially when multiple teams send sensitive communications.

Content Feed

Related media

An adviser reviewing a client review pack at a desk, with a laptop open beside the printed papers

Sending Suitability Reports and Review Packs Securely, and Evidencing Delivery

Send suitability reports and review packs securely, understand what access records show, and plan client follow-up, replies, and document retention.

Remote check in a home office
About our product
21 10 26

How to Run Remote ID, KYC, and AML Checks for Clients

A clear guide to remote ID, KYC, and AML checks for clients: what each check covers, how to send a request, the client steps, and what you receive back.

Colleagues assessing a remote check provider
Digital Identity
20 10 26

Digital ID and the Money Laundering Regulations: A Simple Guide to Remote Checks

What the Money Laundering Regulations and 2026 government guidance say about checking clients remotely with digital ID, with practical examples for firms.