Tutanota is an independent ad-free secure email and calendar provider. You can follow at:

➡️ @Tutanota

The official site is at tutanota.com

Tutanota's mobile app is FOSS and available from , Google Play and iPhone App Store.

Protonmail is an ad-free independent encrypted email provider. You can follow their official account at:

➡️ @protonmail

...they also have an account for their VPN service:

➡️ @protonvpn

...and their calendar service:

➡️ @ProtonCalendar

The official site is at protonmail.com

K-9 Mail is a free open source e-mail app for Android. You can follow the official account at:

➡️ @k9mail

The official site is at k9mail.app

It's available from @fdroidorg and Google Play.

Delta Chat is a free open source encrypted messaging system that works through email accounts. You can follow at:

➡️ @delta

It's available for Android, iOS, Windows, Mac and Linux from the official site at delta.chat

Mastodon

This is a brand new server run by the main developers of the project as a spin-off of mastodon.social 🐘 It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!