Best Email Encryption Software in 2026 | Top Rated

Paubox is the best email encryption software for most small teams in 2026. Encryption is automatic, recipients need no portal or password, and Email Suite starts at $32 per month billed annually. If you want to encrypt on top of Gmail or Microsoft 365 with key control, Virtru publishes three packages from $119 per month. Egress and OpenText, the two enterprise-flavored names, publish no prices at all.

Email encryption software makes sure only the intended recipient can read a message and its attachments. The tools differ in three ways that matter. Some encrypt on top of the mail you already use, and Proton replaces it. Some make the recipient click through a secure portal, while others deliver straight to the inbox. And a few hide their price behind a demo request. If you are weighing threat protection instead, start with our email security software roundup. Prices and features below were verified against vendor pricing pages and documentation in October 2026.

When comparing email encryption software for Outlook with email encryption software for Gmail, begin with the mail system you already run and the recipient experience you need. Encrypted email for business may mean an add-on to that system or a replacement provider. Ask whether an email encryption service requires a portal, separate credentials or changes to the way staff send messages.

Why You Need Email Encryption Software

• Regulated data stops leaking by default. Automatic policies encrypt messages containing health or payment data before a person has to remember. Our data loss prevention guide covers the broader controls.
• Clients can reply without a security lecture. A good tool lets an outside recipient open and answer a message in a browser, with no account to build.
• Attachments are protected, not just bodies. Contracts and patient records travel as attachments, and TLS alone does not protect them once a server stores them.
• You can prove it to an auditor. Audit logs and policy reports turn "we think it was encrypted" into evidence. See also our security compliance guide.
• Sent mail can be pulled back. Revoke and expiry controls, where they exist, limit the damage of a wrong-address mistake.

How We Evaluated

Each product was scored on pricing transparency, recipient experience, MCP and API maturity, and deployment flexibility. Facts come from each vendor's own pricing pages, product pages and documentation. Where a vendor sells by quote, we say so and do not guess, and where an official page would not load we label the substitute source. The full approach is on our methodology page.

Mimecast and Proofpoint were left out on purpose. Both are covered in our email security roundup, where their threat protection is the headline, and encryption is a feature of those suites rather than the reason to buy them.

1. Paubox

Paubox is built for healthcare email, and it makes encryption the thing you never think about. Outbound mail is encrypted automatically and recipients open it in their normal inbox, with no portal, no password and no extra steps.

Pricing: USD, per sender, with a 5-sender minimum. Email Suite Standard is $32 per month billed annually ($42 monthly), Plus is $65 annually ($85 monthly), and Premium is $75 annually ($98 monthly), for 1 to 5 senders. At 10 senders the annual rates are $85, $128 and $143 per month. Over 100 senders is custom. A 14-day trial is offered, and there is no free Email Suite plan.

Top Features

• Automatic encryption of all outbound email
• No recipient portals, passwords or extra steps
• Works in Google Workspace and Microsoft Outlook
• Display-name spoofing protection and phishing filtering on Plus
• Unlimited archiving with search and export on Premium
• Data loss prevention that blocks sensitive content on Premium

Pros

• Recipients never create an account
• HIPAA business associate agreement and HITRUST r2 certification
• Published USD prices and a 14-day trial

Cons

• Per-sender pricing climbs quickly with team size
• Cloud only, and the encryption mechanism is not explained on pages we read

AI/MCP Integration: Official. Paubox documents a hosted MCP server at mcp.paubox.com, with a local option, that lets AI assistants send HIPAA-compliant email, check delivery status and work with Paubox Forms. The docs say the API key stays server-side.

API Integration: Yes. Paubox publishes REST and SMTP email APIs, marketing and forms APIs, OpenAPI specs and SDKs for C#, Go, Java, Node.js, Perl, PHP, Python, Rails, Ruby and Rust at docs.paubox.com.

Cloud Based: Yes. SaaS layered on Google Workspace or Microsoft 365. A self-hosted option is not documented as of October 26, 2026.

Platforms: Google Workspace and Microsoft 365 with Outlook; the company says 9,000 or more US healthcare organizations use it.

Best For: Healthcare practices and other regulated small teams that want encryption with zero friction for patients and partners.

Our take: Choose Paubox when recipients must not be asked to do anything. Check the sender count first, because the per-sender model is cheap at 5 and pricey at 50.

Editor score: 4.6/5. Frictionless delivery, published USD prices, an official MCP server and open API docs earn the top spot; per-sender scaling and a cloud-only model cost it points.

2. Virtru

Virtru encrypts on top of the mail you already run. Its Gmail extension and Outlook add-in add a one-click encrypt toggle, and recipients read the message in Secure Reader in a browser with no new account.

Pricing: USD, per package, billed annually, each package including 5 users. Starter is $119 per month for encrypted email and attachments on Microsoft 365 and Google Workspace. Business is $219 per month and adds encrypted file sharing, compliance features and Google Vault integration. Compliance is $499 per month and adds hosted private key management, Google Workspace Client-Side Encryption support, FedRAMP moderate authorization and FIPS 140-3 validated encryption. Enterprise is custom. Extra users are sold at an unpublished lower rate, and no free plan or trial is listed.

Top Features

• Gmail extension with a one-click encrypt toggle
• Outlook add-in for encrypted email
• Encrypted attachments and files with access control
• Secure Reader for browser access by recipients
• Private Keystore and Google CSE key hosting
• Gateway for policy-based encryption and an Audit Log API

Pros

• Gmail, Google Workspace, Outlook and Microsoft 365 all supported
• Customer-controlled keys on higher packages
• Published package prices

Cons

• No per-user price and no trial listed
• Key control and FedRAMP sit behind the $499 tier or an add-on

AI/MCP Integration: None found. We found no Virtru MCP server on a fetched page or in search as of October 26, 2026; we did not inspect the company's GitHub organization, so a community server is not ruled out.

API Integration: Partial. Virtru's navigation lists a developer experience page built around the open Trusted Data Format, and a GitHub organization exists. We did not read the SDK docs, so treat API depth as unverified.

Cloud Based: Yes, SaaS. Customer-hosted key storage is available through Private Keystore. Whether the Data Gateway can run on premises was not verified.

Platforms: Gmail, Google Workspace, Outlook and Microsoft 365, with compliance pages for HIPAA, GDPR, CJIS, CMMC, FERPA, ITAR, PCI and others.

Best For: Teams already on Google Workspace or Microsoft 365 that want encryption layered on, with a path to customer-held keys.

Our take: Choose Virtru when you need Gmail and Outlook covered and key control matters. A 5-user Starter is $1,428 a year, so price out your headcount before assuming it is the cheap option.

Editor score: 4.5/5. Broad mail coverage and clear packages lead; no MCP and an unverified API cost it points.

3. Microsoft Purview Message Encryption

Microsoft's own encryption is the successor to Office 365 Message Encryption. It is built on Azure Rights Management and lives inside the Microsoft 365 plans many businesses already pay for.

Pricing: Bundled, not sold alone. Microsoft's service description says Azure Information Protection Plan 1, added to plans such as Exchange Online Plan 1 or 2, Microsoft 365 Business Basic or Business Standard, gives the rights to use Message Encryption. Whether Business Premium includes it was not confirmed on a page we could read. Business Premium lists at $22.00 per user per month on an annual subscription ($26.40 monthly), per Microsoft's pricing page as returned in search. Prices for the other plans were not confirmed.

Top Features

• Built on Azure Rights Management
• Encrypt, Do Not Forward and encrypt-only options
• Mail flow rules that encrypt by keyword or recipient
• Encrypted message portal for non-Outlook recipients
• Advanced Message Encryption with branding, expiry and revocation
• Customer Key to bring your own encryption keys

Pros

• No new vendor if you already use Microsoft 365
• Outlook recipients read protected mail natively
• Gmail and Yahoo recipients can open mail through a portal

Cons

• Revocation and expiry work only for external recipients reading through the web portal
• Advanced features need higher-tier licensing

AI/MCP Integration: Official, preview, and limited. Microsoft documents MCP servers for Microsoft 365 mail operations such as sending and replying, but we found no server that covers encryption or Purview settings.

API Integration: Partial. Microsoft Graph has mail APIs. A dedicated Message Encryption API is not documented as of October 26, 2026, and administrators configure encryption through Exchange Online PowerShell and mail flow rules.

Cloud Based: Yes, through Azure RMS and Exchange Online. Self-hosted is not offered, and on-premises Exchange hybrid support was not confirmed.

Platforms: Outlook for Windows, Mac, web, iOS and Android read protected mail natively; other clients use the portal, and a free OME Viewer app exists on iOS and Android.

Best For: Organizations already standardized on Microsoft 365 that want encryption without another contract.

Our take: Choose Microsoft when the license is already on the invoice. Confirm in writing that your exact plan includes Message Encryption, because we could not verify Business Premium on a readable Microsoft page.

Editor score: 4.4/5. Bundled value and native Outlook delivery lead; license ambiguity and portal-only revocation keep it below the top two.

4. Proton Mail

Proton Mail does not encrypt your existing mailbox. It replaces it. You move to Proton's hosted, Swiss-jurisdiction service, where mail between Proton users is end-to-end encrypted and stored with zero-access encryption.

Pricing: USD on the business pages, per user, billed annually. Workspace Standard is $12.99 per user per month ($155.88 a year) with 1 TB per user and 15 custom domains. Workspace Premium is $19.99 per user per month ($239.88 a year) with 3 TB per user and 20 custom domains. Both include a 14-day trial and a 30-day money-back guarantee. Monthly prices were not shown on the official pages.

Top Features

• Zero-access encryption of stored inbox mail
• End-to-end encryption between Proton users
• Password-protected emails for external recipients
• OpenPGP support with key export
• TLS in transit to other providers
• Encrypted calendar, Drive and Docs in the same suite

Pros

• ISO 27001 certified and SOC 2 Type II audited
• Swiss jurisdiction, outside US law
• Productivity suite and VPN bundled

Cons

• You must migrate mailboxes and use Proton's apps or Bridge
• Subject lines and header metadata are not end-to-end encrypted

AI/MCP Integration: None official. We found only community MCP servers, mostly built on Proton Mail Bridge, and none under Proton's own organization as of October 26, 2026.

API Integration: Not documented as of October 26, 2026. Community tools rely on Bridge because no first-party mail API was found.

Cloud Based: Yes. No self-hosted option appears on any page we read.

Platforms: Web, iOS, Android, macOS, Windows and Linux, plus Bridge for third-party mail clients.

Best For: Small teams that value privacy jurisdiction and are willing to change mail providers.

Our take: Choose Proton when privacy posture is the buying criterion and moving mailboxes is acceptable. A HIPAA business associate agreement was not mentioned on the pages we read, so regulated US healthcare teams should look elsewhere first.

Editor score: 4.2/5. Strong audited encryption and clear prices help; mailbox migration, missing API and MCP, and metadata exposure cost it points.

5. Egress Protect

Egress sells policy-based encryption with fine control after the message leaves, including revoke, time limits and geolocation limits. It now carries the line "Egress, a KnowBe4 Company" on its site, following KnowBe4's 2024 acquisition.

Pricing: Not published. The site has no pricing page and a "Get a Demo" call to action. A free trial is not documented as of October 26, 2026.

Top Features

• Policy-based automatic and sender-initiated encryption
• 256-bit AES for content and attachments
• Secure web portal for recipients
• Revoke access after sending, with time and geolocation limits
• Block editing, copying and downloading
• Recipient authentication with MFA and trusted-recipient learning

Pros

• Post-send controls beyond most rivals
• Cloud, hybrid and on-premises deployment
• FIPS 140-2 and ISO 27001 listed

Cons

• Demo-only sales process
• Google Workspace support is not documented

AI/MCP Integration: None documented as of October 26, 2026. We did not search for community servers.

API Integration: Not documented. The site mentions a cloud-native API architecture and a Microsoft 365 integration API, but we found no public docs URL.

Cloud Based: Yes, and also hybrid or on-premises, according to the product page.

Platforms: Outlook desktop add-in, Outlook on the web, Microsoft 365 integration with Purview Information Protection, a mobile app and a browser portal.

Best For: Microsoft-centered organizations that need revocable, auditable messages and may require on-premises deployment.

Our take: Choose Egress when control after sending is the requirement. Expect a demo call, and ask about the KnowBe4 transition before signing a multi-year term.

Editor score: 4.1/5. Post-send control and flexible deployment lead; opaque pricing, a Microsoft-only story and a brand in transition cost it points.

6. Hushmail

Hushmail is a long-running encrypted email host aimed at small practices, with healthcare, legal and small business plans. It works as a full mailbox or alongside an existing email account.

Pricing: Small Business is "as little as $10.79 per month", shown with a dollar sign and no stated currency, with a 60-day money-back guarantee and no free trial. Healthcare is "starting at $11.99 per month" and offers a 14-day free trial. Per-user rates for the other tiers were not readable on the pricing page, so they are not documented here.

Top Features

• Encrypted email using TLS and OpenPGP
• Secure web page for recipient reading and replies
• Recipient sign-in with Google, Apple or Microsoft
• Encrypted, e-signable forms and templates
• Signed HIPAA business associate agreement
• Custom domain support

Pros

• Low entry price
• Recipients need no software
• Healthcare plan with a business associate agreement

Cons

• No public API or MCP server
• No Android app mentioned

AI/MCP Integration: None found as of October 26, 2026. No official MCP server is documented, and we did not search for community servers.

API Integration: No. No public API is documented on any page we read.

Cloud Based: Yes, hosted SaaS. Self-hosted is not documented.

Platforms: Web in Chrome, Safari, Firefox and Edge, a free iPhone app, and Apple Mail or Outlook access per the official page.

Best For: Solo practitioners and very small clinics or law offices that want a simple encrypted mailbox and a signed agreement.

Our take: Choose Hushmail when the team is tiny and compliance paperwork matters more than automation. Check the per-user price for your headcount, because the "as little as" figure is for the smallest setup.

Editor score: 3.9/5. A friendly price and healthcare focus help; no API or MCP and unclear tier pricing hold it back.

7. OpenText Core Email Encryption

OpenText Core Email Encryption is the former Zix email encryption, now sold under OpenText Cybersecurity. It works as a cloud gateway that scans outbound mail and picks S/MIME, TLS or a secure portal for each recipient.

Pricing: Not published. Per-user subscription terms are available through sales, and no dollar figures or marketplace prices were found. The product page shows demo and data sheet options; a trial is unconfirmed.

Top Features

• Automatic policy-based encryption of outbound email
• Data loss prevention filters for subject, body and attachments
• Encrypt, quarantine or block actions per policy
• Best Method of Delivery choosing S/MIME, TLS or portal
• Secure Compose portal for external senders
• Compliance and audit reporting

Pros

• Delivery method chosen per recipient
• Recipients need no software
• Policy-driven DLP in the same service

Cons

• No published pricing
• Mail platform and add-in support is not documented on the product page

AI/MCP Integration: None found as of October 26, 2026. No OpenText page we checked mentions one.

API Integration: None found. A public API is not documented as of October 26, 2026.

Cloud Based: Yes, through OpenText Secure Cloud. No on-premises option was mentioned.

Platforms: Recipients use portals on any device and any webmail client. Microsoft 365 and Google Workspace support is not documented on the pages we checked.

Best For: Existing Zix or OpenText customers, and regulated mid-size organizations that want DLP-driven encryption from a large vendor.

Our take: Choose OpenText when a policy gateway with DLP is the goal and you already deal with the vendor. Branding is slightly inconsistent across OpenText pages, so confirm the exact SKU in the quote.

Editor score: 3.8/5. Per-recipient delivery logic is good; hidden pricing and thin public documentation put it last.

Comparison Table

How to Choose

To choose the best encrypted email service for small business, compare the full sender count, the recipient workflow and any required contracts before comparing the headline price.

• Decide whether to add encryption or replace the mailbox. Proton and Hushmail host your mail; Paubox, Virtru, Egress and OpenText sit on top of it.
• Count senders, not just users. Paubox bills by sender with a 5-sender minimum, while Virtru bundles 5 users per package.
• Test the recipient experience. Ask a real client to open a message in each trial. Portal-free delivery, as in Paubox, beats a click-through for patient mail.
• Check your mail platform. Egress documents Outlook and Microsoft 365 but not Google Workspace, and OpenText does not list either on its product page. Our email client software guide covers the clients on the other end.
• Look at key control. Virtru's Private Keystore and Microsoft's Customer Key matter if you must hold your own keys.
• Get the business associate agreement in writing for any healthcare use, and ask for the price at your headcount before the demo ends.

What This Actually Costs

Take a five-person small business using published numbers. Paubox Email Suite Standard is $32 a month billed annually ($384 a year) for up to 5 senders. Virtru Starter is $119 a month ($1,428 a year) for 5 users. Proton Workspace Standard is 5 users at $12.99, or $64.95 a month ($779.40 a year), though it replaces your mail host and bundles storage and apps. Microsoft 365 Business Premium is 5 users at $22.00, or $110 a month ($1,320 a year), if your plan includes Message Encryption, which we could not confirm for that tier. Hushmail Small Business starts at $10.79 a month, but its page does not say how the price scales to 5 users. Egress and OpenText need a quote, so a team this size cannot budget for them from public pages.

Final Thoughts

Pick Paubox if patients or clients should never be asked to do anything and the sender count is modest. Pick Virtru if you live in Gmail or Microsoft 365 and want a path to your own keys. Pick Microsoft Purview Message Encryption if the license is already paid for and your plan is confirmed. Proton is a mailbox decision more than an encryption add-on, Hushmail fits the tiniest practices, and Egress and OpenText reward buyers who enjoy demo calls. Only one of the seven documents an official MCP server, which says something about how early AI-agent access still is in this category. Verify every price against the vendor's page before you buy, because these change often.