Proton vs Sendmux
Both are Communication tools. Below, the differences that matter: verified pricing, editorial scores and who each one is really for.
Proton: Proton offers end-to-end encrypted email, calendar, VPN, and storage with a free tier and paid plans from $3.99/mo. Pricing: Free · from $3.99/mo for Mail Plus · from $9.99/mo for Proton Unlimited. (data verified June 2026)
Sendmux: Sendmux is a usage-based email API for AI agents, with inboxes, SDK, CLI, and MCP support. Pricing: from $0.15/1k recipients. (data verified August 2026)
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At a glance
 Proton ◆ |
 Sendmux | |
|---|---|---|
| Rating | — | — |
| Pricing | Free · from $3.99/mo for Mail Plus · from $9.99/mo for Proton Unlimited | from $0.15/1k recipients |
| Pricing model | Freemium | — |
| Category | Communication | |
| Visit website → | Visit website → | |
Editorial scorecard
Editorial score from our review methodology — not user ratings.
| Ease of use | 7.5 | 7.5 |
| Features depth | 8.5 | 8.5 |
| Value for money | 8.0 | 7.0 |
| Support quality | 6.5 | 6.5 |
| Integrations | 5.5 | 8.0 |
| Scalability | 7.0 | 7.5 |
| Documentation | 7.5 | 7.0 |
| Onboarding speed | 8.0 | 8.0 |
| Overall | 7.3 | 7.5 |
Frequently asked questions
What is Proton?
Proton offers end-to-end encrypted email, calendar, VPN, and storage with a free tier and paid plans from $3.99/mo.
What is Sendmux?
Sendmux is a usage-based email API for AI agents, with inboxes, SDK, CLI, and MCP support.
How much do Proton and Sendmux cost?
Proton: Free · from $3.99/mo for Mail Plus · from $9.99/mo for Proton Unlimited. Sendmux: from $0.15/1k recipients.
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