Compare Letterbox vs. Proton Mail

Who has access to your emails? In the case of traditional emails, they can be viewed by you, the recipient, all email service providers, and potentially others. However, with end-to-end encryption, only the sender and intended recipients have the ability to read those messages. The iOS application Letterbox simplifies the use of end-to-end encryption, is compatible with a majority of email services, and utilizes the standard encryption protocol OpenPGP. While Letterbox functions similarly to other common email applications, it highlights the security status of both incoming and outgoing messages, allowing users to differentiate between confidential and insecure emails. As a free open-source email client on iOS, Letterbox is part of an ongoing research initiative at Freie Universität Berlin. Though still under development, users will soon be able to access the app on their devices through Apple's TestFlight platform, ensuring that secure communication is more accessible than ever. This advancement aims to enhance user awareness regarding email security while providing a user-friendly experience.

Secure your company’s communications with Proton Mail — the business email solution trusted by over 50,000 organizations. With end-to-end encryption built in, your internal and external communications stay confidential by default. Proton Mail helps your business meet GDPR, HIPAA, and other compliance standards, while giving you full control over your data under strong Swiss privacy laws. Empower your team with encrypted email and calendar, support for your custom email domains, professional branding, and simple migration from providers like Google Workspace or Microsoft 365 — no IT team required.