MailChat 1.4.1 beta adds editing of existing open Thunderbird drafts.

Open a saved draft in Thunderbird, then use the new list_drafts, read_draft and update_draft tools in Codex. Changes to the body, subject, To and Cc are saved in the original composer. Attachments, signature, quoted history and thread information outside the requested changes are retained. Stale review hashes and uncertain retries are rejected. Editing never sends mail; edited drafts are sent manually.

Closed drafts must first be opened manually in Thunderbird. No new permissions or Experiment APIs are required. Drafts-only remains the default.

Update both components: download MailChat-Windows-1.4.1.zip from https://github.com/andrea199/mailchat-for-thunderbird/releases/tag/v1.4.1-beta.1 , extract it, run Install.cmd, install the 1.4.1 XPI and restart Codex. Requirements: Windows, Thunderbird 153+, Node.js 22+ and Codex desktop with local MCP support.

Validation: all 16 automated tests passed, and the rebuilt XPI matched the released package. Clean-profile Thunderbird/Codex end-to-end testing remains outstanding; this is a beta release.

First public beta of MailChat for Thunderbird.

Default drafts-only mode blocks sending from the chat. Optional autonomous sending requires explicit activation in both the Windows installer and Thunderbird settings, plus compose.send permission.

Search and read local mail, download selected attachments, prepare new drafts and native replies with account signature and RFC-linked predecessor history. Missing history fails explicitly. Exact draft content and permissions are checked before autonomous sending; uncertain sends are not retried automatically.

Requirements: Windows, Thunderbird 153+, Node.js 22+ and Codex desktop with local MCP support. Download the required Windows bridge and installation instructions from https://github.com/andrea199/mailchat-for-thunderbird/releases/tag/v1.4.0-beta.1 . The XPI alone is not sufficient.

Nine automated mock/HTTP/installer tests passed. Real Thunderbird/Codex end-to-end testing remains outstanding. Beta release, independent project, MIT license.