Reply Monitor

Reply Monitor is a Thunderbird MailExtension that helps you keep track of sent messages that need a reply.

Preview release: Reply Monitor is currently distributed as an unsigned development build. Use the temporary-install workflow for reliable testing. Permanent installation from an .xpi may require a Mozilla-signed package, depending on your Thunderbird configuration.

Features

• Track one or more sent messages with a due date.
• See tracked messages in a dashboard with overdue and due-today counts.
• Update a due date or stop tracking a message.
• Detect incoming replies through standard email reply headers.
• Receive a daily local notification for overdue replies.
• Open the dashboard directly from an overdue-reply notification.
• Scan the last 7 days of received messages on demand to recover replies that arrived while the extension was inactive.
• Open a prefilled follow-up draft from an awaiting-reply dashboard item; Reply Monitor never sends the message automatically.
• Enable reply tracking directly from the message compose window; tracking is created only after Thunderbird confirms that the message was sent.
• Open the original tracked message or the reply received from its dashboard card.
• Preserve tracking records across Thunderbird restarts and message moves by using extension-owned record identifiers.
• Keep all tracking data in Thunderbird local storage; no message data is sent to a third-party service.

Compatibility

• Thunderbird 140 ESR or later.
• Desktop Thunderbird on Windows, macOS, or Linux.

Get Reply Monitor

Download the latest .xpi from the GitHub Releases page.

For installation instructions, testing steps, and troubleshooting, see the Installation guide.

Quick start

1. Open a sent message in Thunderbird.
2. Click the Track reply button in the message toolbar, choose a due date, and save.
3. Open the Reply Monitor toolbar button to see the dashboard.
4. When the recipient replies, the item is marked Reply received. If the extension was inactive, use Scan recent replies in the dashboard.
5. Use Compose follow-up to open a draft, then review and send it yourself.
6. Open Preferences from the dashboard to configure daily reminders and the default follow-up text.

Privacy

Reply Monitor stores tracking records only in Thunderbird's local extension storage. It does not send email contents, recipients, or tracking data to any external service.

License

Reply Monitor is licensed under the Mozilla Public License 2.0.

Authors

• Antonio Morais — modern Thunderbird MailExtension implementation.
• Lin Han — original Reply Monitor extension and concept.

For contributors

node .\tests\background.test.cjs
node .\tests\popup.test.cjs
.\scripts\package.ps1

The generated XPI is written to dist/.

Status

The MVP stages and the first reliability-hardening pass are complete. See release notes for version details.