v2026.3.3

Pelton can now read your mail out of the client you are leaving.

This release contains that one feature and nothing else.

Import from another mail client

Switching used to mean starting from nothing: every account retyped by hand, and any local-only mail left behind. Both halves are covered now.

Your accounts. Pelton reads Thunderbird's configuration and offers to recreate the mailboxes, so you do not retype six servers and ports. It looks where Thunderbird actually installs:

• Linux the distro package, the Flatpak and the Snap, all three
• macOS ~/Library/Thunderbird and ~/Library/Application Support
• Windows %APPDATA%\Thunderbird

If your profile lives somewhere else, you can point at the folder yourself. Passwords cannot come across, so each mailbox asks for its password once.

Your mail. Single messages (.eml), whole archives (.mbox), and Thunderbird's own local folders, including nested ones. Read and flagged state comes with them. Importing the same file twice does not duplicate anything.

Large archives import in the background with a progress bar, so a multi-gigabyte mbox does not freeze the window.

Where to find it

Adding a mailbox now starts by asking whether you are setting one up or coming from another client. That choice appears wherever you add a mailbox: first run, the sidebar, the Mailbox menu, and Settings. There is also a direct entry under Settings, External.

Imported mail stays local

It lands in a new Local Folders section that has no server behind it. It is never synced, never uploaded, and never folded into the unified inbox, so importing a decade of old mail does not bury what is actually new. The section only appears once you have imported something.

Your old client is not touched

Pelton only reads. It never writes, renames or deletes anything in another program's mail store, and it leaves no cache or marker behind. That includes modification times, so the client you are migrating from cannot tell the difference. It is safe to point at a profile you are still using, and safe to run twice.

Nothing about the import touches the network.

Full Changelog: v2026.3.2...v2026.3.3