A Guide To Choosing The Best Email Provider for Financial Services

Choosing the right email service for your firm is essential to protect client data and meet compliance requirements.

From encryption to integration, let's compare the top tools to help you pick the best platform for secure, efficient communication.

Financial services firms handle sensitive client information daily.

Whether you're an independent adviser or a pensions provider, making sure your emails are private, compliant, and easy to manage is critical.

Having worked in secure communications for years, I’ve seen first-hand how the right tools can transform how firms handle information.

This guide compares the leading email providers used by professionals in the financial sector. We’ve assessed each based on:

• Encryption: Is your message secure, even if intercepted?
• Recipient authentication: Can only the intended person open it?
• Secure reply: Can clients respond safely, without needing a paid account?
• Compliance features: Are audit trails, revocation, and data retention supported?
• User experience: How easy is it for you and your clients to use?

We’ve prioritised UK email compliance expectations (GDPR, FCA guidance, and The Pensions Regulator) while keeping the comparisons balanced and practical.

Mailock: Built for Secure Client Communications

Best for: Professionals who need end-to-end encryption, recipient authentication, and secure replies - all within existing email workflows.

• End-to-end AES-256 (Advanced Encryption Standard) encryption for email and attachments
• Multiple recipient ID verification methods: Q&A, SMS, Unipass ID
• Free secure replies for clients
• Message revoke and full audit trails
• Outlook and web app integration
• Designed for GDPR and FCA compliance

Limitations:

• No native integration with Gmail (however, you can use the Mailock web app for secure sends).

Pricing: Mailock Free (limited sends). Mailock Pro ~£9.30/user/month. Enterprise plans from ~£299/company/month depending on volume.

Verdict: Mailock is purpose-built for regulated digital communications.

Though it isn't an email provider as such (you'll still need a provider like Microsoft), it combines encryption, identity verification, tracking, and control - essential for firms handling sensitive client data.

It adds security without disrupting how teams and clients work, and lets you manage your standard emails (non-sensitive ones) as you usually would, using the provider you prefer.

Now, let's take a look at the email providers.

Gmail (Google Workspace): Strong Integration, Growing Encryption Capabilities

Best for: Teams already working in the Google ecosystem who need document collaboration and email under one roof.

• Client-side encryption (CSE) now available for Enterprise users
• Confidential mode adds expiry dates and SMS verification
• Secure portal access for recipients via Gmail
• Vault, DLP, and audit logging on premium tiers

Limitations:

• CSE only available on higher enterprise plans
• Recipient verification limited to email login or OTP
• Complex configuration required for regulated use

Pricing: Free Gmail available. Business Starter from ~£5/user/month. CSE features require Enterprise Plus (~£15-20/user/month).

Verdict: A solid all-rounder for collaboration and document workflows. However, firms using email for sensitive information will require additional tools to meet recipient authentication and audit standards.

Outlook (Microsoft 365): Familiar, Flexible, and Compliance-Ready

Best for: Organisations already using Microsoft tools and requiring robust enterprise controls.

• Microsoft Purview Message Encryption (OME) for internal and external sensitive information
• Secure reply portals for external recipients
• Compliance tooling: journaling, eDiscovery, retention policies
• Do not forward and message recall features available (but limited)

Limitations:

• Recipient ID checks limited to email or login-based verification
• Encryption features depend on E3/E5 or Business Premium configuration
• Requires IT involvement for secure rollout and enforcement
• Message recall works only under specific conditions and is not guaranteed.

Pricing: Business Basic starts at ~£5/user/month. Full Purview encryption tools require ~£17-30/user/month plans.

Verdict: A powerful compliance option if set up correctly, but identity verification and simplicity for external users are still challenges. Firms seeking end-user control and ease of use may need to integrate with additional solutions to deliver sensitive information to customers.

Zoho Mail: Budget-Friendly with Selective Security Features

Best for: Startups and small firms looking for low-cost custom domain email.

• Free tier for up to 5 users with 5GB each
• S/MIME encryption available on Premium plans
• Integration with Zoho apps (CRM, Projects, Docs)
• Admin controls and email archiving as add-ons

Limitations:

• No built-in recipient authentication or identity checks
• No secure reply portal for clients
• S/MIME setup requires manual certificate management

Pricing: Free for up to 5 users. Paid plans from ~£1/user/month. Premium plan with S/MIME at ~£3.50/user/month.

Verdict: An affordable entry point with decent features for small teams. However, the lack of recipient verification and reply security limits its suitability for financial communications.

Yahoo Mail: High Storage, Low Security

Best for: Personal use or data archiving - not business communications.

• 1TB free storage for emails and attachments
• Basic phishing and spam filtering
• Disposable email addresses included in Yahoo Mail Plus

Limitations:

• No end-to-end encryption for email content
• No recipient authentication or compliance tracking
• Historical breaches impacting billions of accounts (2013-2014)

Pricing: Free plan available. Yahoo Mail Plus ~£3-£5/month removes ads and adds support.

Verdict: Generous storage makes it viable for non-sensitive use, but a complete lack of business-grade encryption or compliance support rules it out for regulated sectors.

Titan: Small Business Email with Helpful Add-Ons

Best for: Small businesses wanting branded email with scheduling and automation tools.

• Custom domain email and mailbox branding
• Email scheduling, templates, and read receipts
• Two-factor authentication for access security

Limitations:

• No end-to-end encryption or identity checks
• No secure reply or message revoke
• Limited integrations outside email workflow

Pricing: From ~£2/user/month via hosting partners or domain registrars.

Verdict: A well-designed platform for small businesses focused on email marketing or basic communications, but not designed for firms handling confidential client data.

Feature Comparison Summary

Let's compare the features of each option against the requirements of the financial services for securing sensitive information.

Security and Compliance Considerations

Email compliance isn’t just about encryption - it’s about control.

Regulatory expectations such as those outlined by the FCA, ICO, and The Pensions Regulator require firms to verify recipients, track delivery, and prevent unauthorised access.

• Mailock: End-to-end encryption, recipient authentication, audit trail, revoke, and secure replies - all aligned to UK financial compliance needs. Integrates with Outlook.
• Outlook: Strong encryption and compliance tools with the right configuration, but lacks granular recipient ID checks by default.
• Gmail: Secure and scalable, but compliance controls require Enterprise-tier CSE setup.
• Zoho, Titan, and Yahoo: Incomplete toolsets for secure or compliant financial communications.

Verdict: The Smart Choice for Regulated Communication

For firms operating under strict regulatory expectations, not every email solution fits the bill.

Popular platforms like Gmail and Outlook offer strong foundations, but most require add-ons, advanced tiers, or manual configuration to meet UK compliance needs.

Mailock delivers the control of enterprise tools with the usability of consumer platforms, enabling professionals to:

• Send encrypted messages with built-in recipient authentication
• Enable free, secure replies from clients and customers
• Revoke access and track delivery with complete audit trails

It integrates directly into your existing inbox and works out of the box to help meet compliance with GDPR, FCA, and Consumer Duty guidance.

"Without recipient authentication, encryption alone isn’t enough for regulated communications.

Mailock gives our clients the tools they need to meet compliance without compromising on convenience."

Paul Holland, Founder, Beyond Encryption

FAQs

Which Email Service Is Best for Compliance?

Mailock is the only solution in this comparison built specifically for regulated client communications, combining encryption, authentication, and audit features.

Can Mailock Replace My Existing Email Provider?

No - Mailock works alongside your existing provider (such as Outlook or Gmail) to add secure sending and compliance controls.

Does Gmail Meet Financial Sector Requirements?

Gmail with CSE can meet some requirements, but lacks native recipient authentication. Setup requires Enterprise-level licensing and IT support.

What Does Recipient Authentication Mean?

It makes sure only the intended recipient can open the message - even if it’s misaddressed or intercepted. This goes beyond just sending to the right email address.

Is There a Free Version of Mailock?

Yes. Mailock Free lets clients receive and reply securely. Paid plans unlock full sending and enterprise features.

References

FCA Handbook, Financial Conduct Authority, 2024

Guide to Data Protection, Information Commissioner's Office, 2024

Mailock Security Features, Beyond Encryption, 2024

Reviewed by

Sam Kendall, 24.07.25