What are the best email encryption software?

The "best" email encryption software depends heavily on your specific needs, technical comfort level, and who you're communicating with. There isn't a single "best" solution for everyone, as different approaches offer varying levels of security, ease of use, and compatibility.

Here's a breakdown of the top options, categorized by their approach:

---

### 1. Dedicated End-to-End Encrypted Email Services (Easiest for Individuals)

These services build encryption directly into their platform, making it very easy to use, especially when communicating with other users on the same service. For external recipients, they often use a password-protected link system.

* **ProtonMail:**

* **Pros:** Widely regarded as one of the best for privacy and security. Strong end-to-end encryption (E2EE) by default, based in Switzerland (strong privacy laws), open-source, audited, user-friendly interface, mobile apps, encrypted calendar and drive. Can send password-protected emails to non-ProtonMail users.

* **Cons:** Free tier has limited storage and features. Full E2EE only works seamlessly with other ProtonMail users.

* **Best for:** Individuals and small businesses prioritizing privacy and ease of use, willing to potentially switch email providers.

* **Tutanota:**

* **Pros:** Excellent E2EE, even encrypts subject lines and contacts (which ProtonMail doesn't by default). Open-source, based in Germany (strong privacy laws), very affordable premium plans, good mobile apps.

* **Cons:** Interface can be less polished than ProtonMail for some. Full E2EE only works seamlessly with other Tutanota users.

* **Best for:** Individuals and small businesses looking for a highly secure, open-source, and cost-effective E2EE solution.

* **StartMail:**

* **Pros:** Based in the Netherlands, offers PGP encryption built-in, allows sending encrypted messages to non-StartMail users via a password-protected portal. Good for those who want PGP without the manual setup.

* **Cons:** Not as widely known or used as ProtonMail/Tutanota.

* **Best for:** Users who want a balance of ease of use and PGP compatibility, especially if they need to communicate with non-encrypted users frequently.

* **Mailfence:**

* **Pros:** Based in Belgium, offers PGP and S/MIME support, encrypted calendar, documents, and contacts. Good for users who want more control over their encryption methods.

* **Cons:** Interface can be a bit more complex than ProtonMail/Tutanota.

* **Best for:** Users who appreciate flexibility in encryption standards and a comprehensive suite of privacy tools.

---

### 2. Client-Side Encryption (PGP/GPG & S/MIME)

These methods involve encrypting emails directly on your device before they leave your email client. They offer the highest level of control but require more technical setup and coordination with recipients.

* **GnuPG (GPG) with Email Clients (e.g., Thunderbird, Outlook, Apple Mail):**

* **How it works:** GPG is the open-source implementation of the OpenPGP standard. You generate a public/private key pair. You share your public key, and others use it to encrypt messages to you. You use your private key to decrypt.

* **Software:**

* **Thunderbird (with built-in OpenPGP):** Thunderbird now has OpenPGP support integrated, making it one of the easiest ways to use PGP.

* **Mailvelope (Browser Extension):** A browser extension that integrates PGP encryption into webmail services like Gmail, Outlook.com, etc. It's a good way to use PGP without changing your email provider.

* **Gpg4win (Windows) / GPGTools (macOS):** Software suites that provide the core GnuPG tools and often integrate with email clients like Outlook or Apple Mail.

* **Pros:** Open standard, very strong encryption, works with *any* email provider, high level of control over your keys.

* **Cons:** Steep learning curve, key management is crucial and can be complex, *both sender and receiver must use PGP* and exchange public keys. Not ideal for casual use.

* **Best for:** Tech-savvy individuals, journalists, activists, or anyone needing maximum control and interoperability with other PGP users, regardless of their email provider.

* **S/MIME (Secure/Multipurpose Internet Mail Extensions):**

* **How it it works:** Similar to PGP but uses certificates issued by a Certificate Authority (CA). Often used in corporate environments.

* **Software:** Built into most major email clients like **Outlook**, **Apple Mail**, and **Thunderbird**.

* **Pros:** Industry standard, good for corporate environments, built into many clients.

* **Cons:** Requires obtaining and managing digital certificates (can be costly or complex), *both sender and receiver must use S/MIME* and have valid certificates.

* **Best for:** Businesses and organizations that need to comply with specific regulations or have an existing S/MIME infrastructure.

---

### 3. Gateway/Cloud-Based Encryption (Primarily for Businesses/Enterprises)

These solutions encrypt emails as they pass through a company's email server or a third-party cloud service. They are often transparent to the end-user but involve trusting the service provider.

* **Zix (now OpenText Cybersecurity):**

* **Pros:** Widely used in healthcare and finance, robust policy-based encryption, easy for recipients (often a secure portal), strong compliance features.

* **Cons:** Expensive, primarily for enterprise, not true end-to-end encryption (Zix holds the keys or decrypts at the gateway).

* **Best for:** Large organizations with strict compliance requirements (HIPAA, GDPR) that need to encrypt emails automatically for all users.

* **Proofpoint Email Protection:**

* **Pros:** Comprehensive suite including encryption, data loss prevention (DLP), and threat protection. Policy-driven encryption.

* **Cons:** Enterprise-focused, complex to set up and manage, expensive.

* **Best for:** Large enterprises needing an all-in-one email security and compliance solution.

* **Mimecast Email Security:**

* **Pros:** Offers email encryption as part of a broader security platform, good for archiving and continuity, policy-based.

* **Cons:** Enterprise-grade, not designed for individual users, less "end-to-end" in the purest sense.

* **Best for:** Businesses looking for integrated email security, archiving, and encryption.

* **Virtru:**

* **Pros:** Integrates well with Google Workspace (Gmail) and Microsoft 365 (Outlook), user-friendly, offers data loss prevention (DLP) and access control.

* **Cons:** Not fully open-source, relies on a trusted third party.

* **Best for:** Businesses heavily invested in Google Workspace or Microsoft 365 that need an easy-to-deploy encryption solution.

---

### Important Considerations When Choosing:

1. **Ease of Use:** How technically comfortable are you and your recipients? Dedicated services are easiest. PGP/S/MIME are harder.

2. **Recipient Compatibility:** Will your recipients also use the same encryption method? This is the biggest hurdle for true E2EE.

3. **Security Model:** Do you need true end-to-end encryption (where only you and the recipient hold the keys), or are you comfortable with a trusted third party handling keys (gateway solutions)?

4. **Cost:** Free tiers exist, but premium features and enterprise solutions can be expensive.

5. **Features:** Do you need encrypted attachments, calendars, cloud storage, or mobile apps?

6. **Trust:** Is the software open-source? Has it been audited? What jurisdiction is the provider in?

---

### Recommendation Summary:

* **For most individuals and small businesses prioritizing privacy and ease of use:** **ProtonMail** or **Tutanota**.

* **For tech-savvy individuals who need maximum control and interoperability with other PGP users:** **Thunderbird with built-in OpenPGP** or **Mailvelope** for webmail.

* **For businesses with compliance needs and existing infrastructure:** **Zix**, **Proofpoint**, **Mimecast**, or **Virtru** (depending on your ecosystem).

Remember, the best encryption is the one you *actually use* consistently.