Fastmail Bulk Folder Mover

WHAT IT DOES

Fastmail Bulk Folder Mover solves a common email organization challenge: moving multiple Fastmail emails between folders is tedious when done one at a time. While Fastmail allows individual folder moves, there is no native way to select and move many emails simultaneously. This tool reads your current Fastmail inbox or folder view, detects all visible emails, and displays them in a scrollable checklist with subject lines, senders, and current folder locations. You select the emails you want to move, choose a target folder from a dropdown that detects all your existing folders, and click "Move Emails." The tool then processes each selected email sequentially through Fastmail's JMAP API, updating the folder location while preserving all other email data. You can also add new folders directly from the tool. A preview shows your selection before moving, and progress tracking shows each email as it's processed.

WHERE IT RUNS

This extension panel runs directly inside your browser as an overlay on any Fastmail inbox or folder view. It works on the inbox, folder views, and search results. The tool detects emails from the page's DOM and uses Fastmail's JMAP API (via GM_xmlhttpRequest) for folder moves. It requires no additional API keys beyond your existing authenticated session — the tool extracts your access token from the page.

HOW TO USE

After installing the BotGentz extension and activating Fastmail Bulk Folder Mover, navigate to your Fastmail inbox or folder view. Click the extension icon in your browser toolbar to open the panel. The tool automatically detects all emails displayed on the current page. Each email appears with its subject, sender, and current folder alongside a checkbox. Use the "Select All" toggle or individually check emails. Next, choose a target folder from the dropdown — the tool detects all existing folders in your Fastmail account. You can also add a new folder by entering a name and clicking "Add Folder." The preview section shows how many emails are selected and the target folder. Finally, click "Move Emails." The tool processes each email with a 500ms delay, showing progress as each email is moved. A notification appears when all emails have been processed. Click "Export Report" to copy a report of all email folder data to your clipboard in CSV or JSON format.

TECHNICAL OPERATION — Fastmail JMAP API Folder Updates

This tool uses Fastmail's JMAP API to perform folder moves reliably. It first extracts the user's access token and account ID from the page (using regex to find `access_token` in scripts or meta tags), then constructs a JMAP request to the `/jmap/api/` endpoint with an `Email/set` method call. The payload contains an `update` object with the email ID and the target `mailboxIds`. The API approach is more reliable than DOM-based simulation because it works independently of Fastmail's UI structure, supports proper error handling with HTTP status codes, and can handle large numbers of emails efficiently without triggering UI event delays. A 500ms delay between updates prevents rate limiting and API congestion. The tool also supports adding new folders via the UI, which are then available for selection. Results can be exported as CSV with proper field quoting for Excel compatibility, or as structured JSON.

THE PANEL

The extension panel is fully draggable and remembers its position per site session. It snaps to the nearest edge of the browser viewport when dragged within 50 pixels of any side. You can collapse the panel to a compact title bar using the minimize button, preserving your selection state. The panel resizes vertically by dragging the bottom edge. Press the Escape key to close the panel instantly without losing your email selection. The preview updates in real-time as you select emails or change the target folder.

PLEASE NOTE

This tool requires the free BotGentz extension to function. The script uses Fastmail's JMAP API and requires your session to be authenticated. It does not store, transmit, or log any email data, folder information, or user activity. All API requests are made locally from your browser session. The tool relies on extracting your access token from the page, which may expire if your session times out. Fastmail may update its DOM structure over time, which could affect email detection; we monitor and release compatibility updates as needed. Folder moves are permanent — review the preview carefully before confirming. The "Add Folder" feature adds the new folder to your Fastmail account via the interface. Export formats include CSV and JSON for maximum compatibility with analysis tools.