Open Source Alternatives is described as ', part of Office Online (not to be confused with https://alternativeto'. There are more than 50 alternatives to for various platforms. The best alternative is ProtonMail, which is both free and Open Source. Other great apps like are Tutanota (Free Personal, Open Source), Disroot (Free, Open Source), Posteo (Paid, Open Source) and Teknik Mail (Paid, Open Source).

    The list of alternatives was last updated Nov 23, 2020