Email Encryption Software for Small Business: 7 Tools Compared
Choosing email encryption for a small business comes down to one trade-off: how much protection you need versus how much work your recipients will tolerate. Some tools deliver protected mail to an ordinary inbox; others require recipients to verify their identity, enter a password, or use a separate inbox.
Choosing email encryption for a small business comes down to one trade-off: how much protection you need versus how much work your recipients will tolerate. Some tools deliver protected mail to an ordinary inbox; others require recipients to verify their identity, enter a password or use a separate inbox.
If you want to keep Gmail or Outlook, compare Virtru, Paubox, PreVeil and OpenText. If you can switch email providers, consider Proton Mail or Tuta Mail. Microsoft 365 users should check whether their plan includes Purview Message Encryption before buying another service.
This comparison covers six third-party tools and one built-in Microsoft option. Transport encryption is not the same as end-to-end encryption : the former protects a message while it travels between mail systems; the latter is designed to keep its contents unreadable to those systems.
What’s new
Using Google Workspace? In , Google announced Gmail end-to-end encrypted messaging in its Android and iOS apps for eligible Workspace customers. The announced availability was Enterprise Plus with an Assured Controls add-on, so check your plan rather than assuming the feature is included. [1]
Key takeaways
- Recipient steps differ: protected mail may arrive in an ordinary inbox or require verification, a password, a portal or another inbox.
- Virtru, Paubox, PreVeil and OpenText offer ways to keep an existing Gmail or Outlook setup; their protection and delivery methods differ.
- Proton Mail and Tuta Mail are options if you can move to a private email provider.
- Check your Microsoft 365 license for Purview Message Encryption before buying another service.
- TLS protects mail in transit; it is not the same as end-to-end encryption.
- Test an external recipient, an attachment and a reply before committing.
Email encryption tools at a glance
| Tool | Best fit | Gmail and Outlook fit | How protected messages are delivered | Recipient’s main step |
|---|---|---|---|---|
| Virtru | Keep existing mail; add end-to-end protection | Works with Gmail and Outlook | Encrypted message and attachments | Open and verify identity if not using Virtru |
| Paubox | Healthcare teams prioritizing easy delivery | Connects to Google Workspace or Microsoft 365 business mail | Automatic TLS delivery; secure link when needed | Usually read in the normal inbox |
| PreVeil | Keep your address; use a separate secure inbox | Runs alongside existing Outlook or Gmail mail | End-to-end encrypted mail | Use PreVeil or set up browser access |
| OpenText Core Email Encryption | Policy-driven protection across a team | Confirm your deployment with the vendor | TLS, message-level encryption or secure portal | Depends on the delivery method |
| Proton Mail | Move to private email hosting | Move mail to Proton; paid users can use supported desktop clients through Bridge | Automatic between Proton users; optional protection outside Proton | External recipients open a password-protected message when used |
| Tuta Mail | Move to private hosting without third-party mail clients | Move mail to Tuta; no Outlook or other third-party client support | Automatic between Tuta users; shared password outside Tuta | External recipients open a link and enter the password |
| Microsoft Purview | Check your existing Microsoft 365 entitlement first | Built into eligible Microsoft 365 setups | Microsoft-managed message encryption | Read in supported Outlook setups or use a portal |
Virtru
- Best fit
- Keep existing mail; add end-to-end protection
- Gmail and Outlook fit
- Works with Gmail and Outlook
- How protected messages are delivered
- Encrypted message and attachments
- Recipient’s main step
- Open and verify identity if not using Virtru
Paubox
- Best fit
- Healthcare teams prioritizing easy delivery
- Gmail and Outlook fit
- Connects to Google Workspace or Microsoft 365 business mail
- How protected messages are delivered
- Automatic TLS delivery; secure link when needed
- Recipient’s main step
- Usually read in the normal inbox
PreVeil
- Best fit
- Keep your address; use a separate secure inbox
- Gmail and Outlook fit
- Runs alongside existing Outlook or Gmail mail
- How protected messages are delivered
- End-to-end encrypted mail
- Recipient’s main step
- Use PreVeil or set up browser access
OpenText Core Email Encryption
- Best fit
- Policy-driven protection across a team
- Gmail and Outlook fit
- Confirm your deployment with the vendor
- How protected messages are delivered
- TLS, message-level encryption or secure portal
- Recipient’s main step
- Depends on the delivery method
Proton Mail
- Best fit
- Move to private email hosting
- Gmail and Outlook fit
- Move mail to Proton; paid users can use supported desktop clients through Bridge
- How protected messages are delivered
- Automatic between Proton users; optional protection outside Proton
- Recipient’s main step
- External recipients open a password-protected message when used
Tuta Mail
- Best fit
- Move to private hosting without third-party mail clients
- Gmail and Outlook fit
- Move mail to Tuta; no Outlook or other third-party client support
- How protected messages are delivered
- Automatic between Tuta users; shared password outside Tuta
- Recipient’s main step
- External recipients open a link and enter the password
Microsoft Purview
- Best fit
- Check your existing Microsoft 365 entitlement first
- Gmail and Outlook fit
- Built into eligible Microsoft 365 setups
- How protected messages are delivered
- Microsoft-managed message encryption
- Recipient’s main step
- Read in supported Outlook setups or use a portal
The table is a shortcut, not a guarantee for every recipient. The details below explain when a portal, password or different app enters the picture.
How we compared the tools
This is a comparison of vendor-published product, support and pricing information, not a hands-on test. We focused on what is encrypted, whether existing Gmail or Outlook accounts stay in place, what an outside recipient must do, and whether a public price is available. Private email hosts are included because switching providers is an alternative to adding software. Purview is included as a Microsoft 365 baseline, although it is not a third-party product.
Tools for keeping your current Gmail or Outlook setup
Virtru — best for end-to-end protection inside familiar mail apps
- Strengths: Virtru works with Gmail and Microsoft Outlook, encrypts message content and attachments, and offers sender controls such as expiration and revoking access. [2]
- Recipient: Someone without Virtru can open a secure message without installing software or creating a new password, but ordinarily must verify their identity first. [3]
- Biggest drawback: That verification step is more work than reading an ordinary email. Watch out: turning off required authentication is an optional feature that Virtru says must be enabled by request; anyone with the link could then open that message. [4]
- Cost: Starter is listed at $119 per month for five users , billed annually. Prices and plan features can change. [5]
Paubox — best for healthcare teams that want little recipient friction
- Strengths: Paubox connects to business Google Workspace or Microsoft 365 mail, protects outbound messages automatically, and usually delivers them straight to the recipient’s inbox. If the receiving server cannot use its required TLS connection, Paubox provides a secure link instead. [6]
- Recipient: Usually nothing beyond opening the email. The secure-link fallback adds a browser step.
- Biggest drawback: Inbox delivery secured with TLS is not end-to-end encryption; the recipient’s mail service receives the message. Watch out: Paubox requires a custom business domain and a supported business email account, not a personal Gmail or Outlook.com address. [7]
- Cost: Paubox lists a $32-per-month minimum , billed annually, covering up to five email addresses. Pricing can change. [7]
PreVeil — best for a separate secure inbox without changing addresses
- Strengths: PreVeil adds an end-to-end encrypted inbox alongside existing Outlook or Gmail mail, lets users keep their email addresses, and offers business administration controls. [8]
- Recipient: Existing PreVeil users can read secure mail there. Others can use browser-based access, which requires a first-time setup; they need not buy a guest license. [9]
- Biggest drawback: The second inbox gives staff one more place to check. Watch out: it does not turn every message in your ordinary mailbox into a PreVeil-encrypted message. [8]
- Cost: A free Basic plan is listed for individuals; the Business plan is listed at $30 per user per month . Confirm current billing terms and any specialized compliance plan before buying. [10]
OpenText Core Email Encryption (formerly Zix) — best for centrally managed rules
- Strengths: Administrators can use policies based on content, keywords or attachments. Delivery options include policy-based TLS, message-level encryption and a secure portal; external contacts can also initiate a protected conversation through Secure Compose. [11]
- Recipient: Delivery may be direct to the inbox or through a portal. Ask for a demonstration using addresses outside your organization rather than assuming one experience fits every message.
- Biggest drawback: More delivery options mean more policy decisions to configure and explain. Watch out: the name Zix still appears in recipient instructions, while the product is now presented under OpenText. [12]
- Cost: Per-user subscriptions are offered, but there is no dependable public dollar figure for this configuration; request a current quote. [12]
Switch to private email hosting
Proton Mail — best if privacy matters and some desktop flexibility helps
- Strengths: Mail between Proton users is end-to-end encrypted automatically. Proton also protects mail stored in its own inboxes and offers paid business plans with custom domains. [13]
- Recipient: For an end-to-end encrypted message to someone outside Proton, use a password-protected email and share the password separately; the recipient opens the message in a browser. Ordinary mail to an external provider is not end-to-end encrypted by default. [14]
- Biggest drawback: Moving your business mail to Proton is a bigger change than installing an add-on. Watch out for Outlook: paid users can connect supported desktop clients through Proton Mail Bridge, but Proton says password-protected messages to non-Proton recipients must be sent from its web or mobile apps, not through Bridge. [15]
- Cost: Business mail uses per-user paid plans; confirm the current U.S. checkout price, taxes and billing period rather than relying on an unrendered price comparison. [16]
Tuta Mail — best if your team can leave third-party mail clients behind
- Strengths: Messages between Tuta users are end-to-end encrypted automatically. Tuta also encrypts the subject of its protected messages and offers business plans with custom domains. [17]
- Recipient: An outside recipient receives a link, enters a password shared through another channel, and can reply in Tuta’s browser-based view. [17]
- Biggest drawback: Tuta does not support Outlook, Gmail or other third-party email clients through IMAP or SMTP. Watch out: protected messages to outside recipients need the shared-password step; a regular external email is not automatically end-to-end encrypted. [17]
- Cost: Business plans are priced per user. Check the current U.S. checkout amount and billing period, which can change. [18]
Already on Microsoft 365? Check this built-in option
Microsoft Purview Message Encryption — best first check for eligible Microsoft 365 teams
Purview is not a third-party add-on . It belongs here because an existing subscription may already cover the need: Microsoft lists Message Encryption with Microsoft 365 Business Premium and several enterprise plans, with an add-on route for certain other plans. Users can apply options such as Encrypt-Only or Do Not Forward, and administrators can create mail-flow rules. Send an encrypted email in Outlook [19]
- Strengths: It works within the Microsoft 365 environment, can encrypt messages to external addresses, and supports both user-selected protection and administrator-defined rules. [20]
- Recipient: A supported Microsoft 365 Outlook recipient may read the protected message in Outlook. Others may use Microsoft’s encrypted-message portal and an available sign-in or one-time code. [19]
- Biggest drawback: Recipient access and available controls depend on the setup. Watch out: Microsoft says expiration and revocation for external recipients require the portal experience, which administrators can enforce. [21]
- Cost: Included with eligible licenses; otherwise, check the price of an eligible plan or add-on for each sender. Licensing can change. [19]
Three checks before you buy
Three checks before you buy
- Send a real test message. Try a Gmail address, a Microsoft 365 address and a recipient outside both systems. Note every sign-in, code and browser step.
- Test the message you actually need to protect. Include an attachment and a reply; check whether the subject, downloaded file and reply get the protection you expect.
- Confirm your requirements. If you handle regulated information, have your compliance adviser review contracts, access controls and retention needs. Encryption alone is not a complete compliance plan.
What can change: Prices, eligible licenses, supported apps and recipient steps. Confirm these with the vendor before committing, especially if your team uses a particular Outlook version or depends on external recipients.
Frequently asked questions
What is the difference between TLS and end-to-end email encryption?
TLS protects mail while it travels between systems. End-to-end encryption is designed to keep the message contents protected from the sending and receiving mail services as well.
What is the best email encryption software for Outlook?
For an add-on, start with Virtru if you want protected messages from a familiar compose window. Check Purview first if your Microsoft 365 license includes it. PreVeil suits teams willing to use a separate secure inbox.
Can I encrypt an email to someone who does not use my software?
Yes, but the experience varies. They may read it in their inbox, open a secure link, verify their identity or enter a password. Test with a real external address before rollout.
Is Proton Mail end-to-end encrypted when I email Gmail?
Not by default. Use Proton’s password-protected email option or arrange compatible PGP encryption when you need end-to-end protection for an outside recipient. [14]
Can I use Tuta Mail in Outlook?
No. Tuta requires its own web, desktop or mobile apps rather than a third-party mail client. [17]
Does encrypted email automatically make a small business compliant?
No. Requirements can also involve contracts, access rules, recordkeeping and staff practices. Ask a qualified adviser about the rules that apply to your business.
Best picks by scenario
- Keep Gmail or Outlook and protect sensitive content end to end: Virtru.
- Make sending effortless for a healthcare team and reading easy for most recipients: Paubox, provided TLS-based delivery fits your requirements.
- Keep your address but separate ordinary and protected conversations: PreVeil.
- Apply detailed encryption rules across a team: OpenText Core Email Encryption.
- Move to a private mail provider: Proton if desktop-client access matters; Tuta if your team is comfortable using its own apps.
- Already on an eligible Microsoft 365 plan: Try Purview before purchasing another service.
Sources
- Google Workspace Updates: Gmail end-to-end encryption on mobile, April 9, 2026
- Virtru: Email Encryption for Gmail and Outlook
- Virtru: How recipients open an encrypted email
- Virtru Support: Require Authentication
- Virtru: Packages and pricing
- Paubox: Email Suite delivery and encryption
- Paubox Support: New-customer requirements and minimum cost
- PreVeil: Encrypted email and existing-mail integration
- PreVeil: Recipient access and product features
- PreVeil: Plans and pricing
- OpenText: Core Email Encryption data sheet
- OpenText: Recipient access and Core Email Encryption FAQs
- Proton: Mail encryption and account options
- Proton: Password-protected email to outside recipients
- Proton: Encryption when using Proton Mail Bridge
- Proton: Business mail plans
- Tuta Support: Encryption, external recipients and third-party clients
- Tuta: Business mail plans
- Microsoft Learn: Purview Message Encryption FAQ and licensing
- Microsoft Learn: Purview Message Encryption overview
- Microsoft Learn: Managing external-recipient portal access
