Free desktop email client from the Mozilla family with calendaring, contacts, chat and strong OpenPGP encryption built in. Revived by community donations after years of neglect, it is proof that users will directly fund software that respects them.
The Preservation Rating scores how well this entry is archived — not how good the software is. It's calculated automatically from what's already on this page: working mirrors, documentation, a reproducible build, a clearly identified license, and complete metadata. Nothing here is entered by hand; it updates itself whenever the entry changes.
