What are the best email encryption software?

The best email encryption options fall into two main categories: **secure email providers** (like Proton Mail, Tuta, StartMail) and **encryption add-ons/gateways** (like Virtru, Paubox, Proofpoint, Mimecast). The “best” choice depends on whether you want a new secure mailbox, to keep using Gmail/Outlook, or to meet regulations like HIPAA.

Below is a concise breakdown so you can pick the right tool for your situation.

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## 1. Best all‑around secure email providers (end‑to‑end)

These services host your email and build encryption in by default. Good if you’re willing to use a new email address or migrate.

**Top options:**

- **Proton Mail** – Switzerland-based, **end‑to‑end encrypted mailbox** with strong privacy laws; widely considered the top all‑around secure email service.[1] It supports PGP, zero‑access encryption of emails at rest, and has business plans.[1][3][7]

- **Tuta (Tutanota)** – Fully encrypted mailbox (emails, attachments, contacts, calendar, even search index) with automatic encryption between users.[1][2] Strong privacy focus and open‑source clients.

- **StartMail** – Dutch provider with **built‑in PGP**; lets you create unlimited aliases and easily encrypt/decrypt with one click in the web interface.[1][2]

- **Mailfence** – Belgium-based, uses **OpenPGP** with an integrated key manager, plus TLS/SSL, HSTS, and perfect forward secrecy for transport security.[1][2]

- **Mailbox.org, Posteo, Runbox, Kolab Now, Zoho Mail** – European and global providers focusing on privacy, some with PGP integration and strong data‑protection compliance.[1]

These are best if you want:

- End‑to‑end encryption tightly integrated

- Strong data‑protection jurisdictions (EU/Switzerland/Norway)

- Less configuration than DIY PGP

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## 2. Best “keep Gmail/Outlook” encryption services

If you want to **keep your existing address** but add encryption, you need a client plug‑in or a gateway.

**User‑side / plug‑in style (good usability):**

- **Virtru** – Often rated top for **controlled encryption in Gmail and Outlook**, allowing message revocation, forwarding controls, and read‑tracking while keeping a familiar interface.[5] It is widely used in regulated sectors and shows up in “best email encryption” rankings.[5][7]

- **FlowCrypt, Mailvelope, SecureMyEmail, Thunderbird + OpenPGP** – OpenPGP‑based tools listed by OpenPGP.org that add PGP encryption on top of existing accounts.[3] These are good for standards‑based encryption but can be harder for non‑technical users.

**Gateway / business‑focused:**

- **Paubox** – A leading **HIPAA‑focused** email encryption service that aims for “invisible” encryption: users send mail normally, encryption happens automatically in transit.[4][7]

- **Proofpoint Core Email Protection** – Enterprise email security platform that includes encryption alongside spam/phishing protection.[7]

- **Mimecast** – All‑in‑one cloud email security suite that includes **policy‑based encryption** as one component.[6][7]

These are best if you want:

- To stay on Gmail, Microsoft 365, or your current provider

- Central control, compliance logging, DLP, and policy rules (especially for organizations)

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## 3. OpenPGP tools and ecosystem

If you want **maximum control** and open standards, consider **OpenPGP‑based** tools:

- OpenPGP.org lists software such as **FairEmail, Delta Chat, FlowCrypt, K‑9 Mail + OpenKeychain, R2Mail2, SecureMyEmail, Thunderbird, Claws Mail** and browser plugins like **FlowCrypt (for Gmail)** and **Mailvelope**.[3]

- Some secure providers (Proton Mail, Mailfence, Hushmail) also support OpenPGP, so you can exchange encrypted messages with external PGP users.[3]

Best for technically comfortable users who want:

- Interoperable encryption that works across providers

- Local control of keys and trust decisions

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## 4. If you need HIPAA / regulatory compliance

If your main concern is **legal compliance** (HIPAA, GDPR, etc.), look at:

- **Paubox** – HIPAA‑centric, often recommended in lists of HIPAA‑compliant email encryption services.[4][7]

- **Virtru** – Used widely for regulated industries, including healthcare and government, with fine‑grained access controls.[5][7]

- **Proofpoint, Mimecast, and similar enterprise gateways** – Common in larger organizations for policy‑based encryption and governance.[6][7]

- **Kolab Now, Zoho Mail** – Emphasize compliance (GDPR, HIPAA‑friendly setups) and secure hosting jurisdictions.[1][7]

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## 5. How to choose among them

Use this quick guide based on your situation:

- **Individual, strongest privacy & new address is fine**

→ **Proton Mail** or **Tuta** (plus StartMail/Mailfence if you like PGP and EU hosting).[1][2][7]

- **Small business / teams wanting a secure provider**

→ **Proton Mail for Business, Mailfence, StartMail, Zoho Mail, Kolab Now**.[1][7]

- **Organization on Microsoft 365 or Google Workspace**

→ **Virtru** (user‑friendly) or **Proofpoint / Mimecast / Paubox** (more policy‑driven, compliance‑heavy).[5][6][7]

- **Technical user wanting open standards & full control**

→ Use **Thunderbird with OpenPGP**, **FlowCrypt/Mailvelope** with Gmail, or other tools from the OpenPGP.org list.[3]

If you tell me whether you are an individual or an organization, what provider you use now (Gmail, Outlook, etc.), and whether you have compliance requirements (HIPAA, GDPR, etc.), I can narrow this to 2–3 concrete recommendations and setup tips.