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Aster MailProton Mail
Freemium

Free plan with 10 GB of storage; paid plans start at $2.99 per month.

 Freemium

Free accounts work in the mobile and web apps; the desktop apps are offered as a free…

Android Windows, macOS, Linux, Android, iOS, Web
  • Mail is encrypted on the device before it leaves
  • 10 GB free with custom domain support
  • End-to-end encrypted email by default
  • Apps for iOS, Android, macOS, Windows, Linux and the web
  • The app only works with astermail.org accounts
  • Young project with a small user base compared with established providers
  • Only works with a Proton account
  • Desktop apps need a paid plan after the trial
Downloadable app, Hosted service Downloadable app, Web application, Hosted service
Open source Closed source
License: AGPL-3.0 License not stated
Account needed Account needed
Not stated if it works offline Not stated if it works offline

Checked October 2, 2026

Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.