Thunderbird

Mozilla's free, open-source desktop mail client.

thunderbird.net
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Price
FreeCompletely free; funded by user donations through MZLA Technologies, a Mozilla subsidiary.
Works on
Windows, macOS, Linux, Android
Based in
United States
Source code
Open source
Encryption
End-to-end encrypted

Thunderbird is Mozilla's long-running desktop mail client and the most capable free option for managing several accounts in one place. It ships with built-in OpenPGP encryption so you can sign and encrypt messages without add-ons and it also handles S/MIME. Being a client rather than a provider, your real privacy still depends on the mailbox you connect to it. It is open source, funded by donations, and now has an official Android app as well. The interface is utilitarian but few clients match its flexibility.

Strengths

  • Built-in OpenPGP encryption, no add-on needed
  • Free, open source, and donation funded
  • Manages many accounts across desktop and Android
  • Backed by Mozilla via MZLA Technologies

Considerations

  • Dated, utilitarian interface
  • Setup can take patience
Listed inEmail Clients

Thunderbird alternatives

BetterbirdFeature-enhanced Thunderbird fork with no telemetryFairEmailPrivacy-obsessed open-source email for Android.K-9 MailVeteran open-source Android client, now part of Thunderbird.Canary MailPolished paid client with built-in PGP encryption.