Glassbird Pro Beta

Turn mail into work that moves forward.

The add-on for Thunderbird on Windows, Linux and Mac.

Mail turns into cards on a board, what's been sitting there comes back by itself, and an AI writes in your style if you want it to.

Coming soon to addons.thunderbird.net.

All features

Board, search and notes are free. Everything else is €29.99, one-off, with 30 days to try.

The board “Studio” with the columns Eingang, Zu erledigen, In Arbeit, Warten auf and Erledigt (inbox, to do, in progress, waiting for, done), shown in German. The cards show mail with sender, date and subject, and notes, with labels such as Dringend (urgent), Print, Web and Angebot (quote), due dates, checklists, comments and a reminder on 19 October.

Reminders and assistant

What you put aside comes back.

A mail comes back at the time you pick, on the board and as a notification. If your question goes unanswered or someone is waiting for you, the assistant speaks up.

The assistant's suggestions above the board, shown in German: Clara Neumann hasn't replied yet, with buttons to move the mail to “Warten auf” (waiting for) and to follow up; Paul Richter and Miriam Kühn are waiting for an answer; Lena Vogt has replied, and her card can move to “Zu erledigen” (to do). Below, the board's columns begin.

Writing with AI

Drafts that sound like you.

A few notes become a mail, with the context you choose. With “My style”, drafts learn from your examples and corrections.

The “Mit KI schreiben” (write with AI) window for a reply to Miriam Kühn, shown in German: the notes at the top, below them the context “Verlauf” (conversation) and “Mein Stil” (my style), the line saying it stays on this computer (Ollama), and the finished draft with the buttons cancel, again and insert.

Send later

Write tonight, send tomorrow at eight. The mail waits in Thunderbird for its time.

Undo send

Wrong recipient, forgotten attachment: you have up to 20 seconds to recall the mail.

Unsubscribe in one click

One click in the bar above the mail, where the newsletter offers it. No more hunting for the link in the small print.

Dashboard

Your day on one page.

Today's and tomorrow's events, unread mail, tasks due and what's in progress on the board. Every tile opens its area.

The dashboard “Guten Abend, Donnerstag, 15. Oktober” (good evening, Thursday 15 October), shown in German, with tiles for the calendar today and tomorrow, the latest unread mail and four flagged, tasks, notes and the three cards in progress on the board.

Notes Free

Notes that know what they're about.

You write with formatting, what's saved is plain Markdown, and every note belongs to a person or a mail. With Pro, it syncs with Nextcloud, Obsidian or Joplin.

The note “Herbstkatalog Nordlicht”, linked to Miriam Kühn, with a checklist, headings, bullet points, a quote and a link to the mail, the format bar above, shown in German. On the left, the list of notes by today, yesterday and the previous 7 days, with colour filters.

All features

What's in Pro.

On three levels: what helps every day, what keeps things organised, and what advanced users need.

  • Free works without a licence
  • AI needs an AI model
  • Companion add-on needs the free companion add‑on

For every day
  • Send later

    At a time you choose. If Thunderbird was closed, the mail goes shortly after the next start.

  • Undo send

    5, 10 or 20 seconds to recall a mail.

  • Check before sending

    Warns about the wrong account, group mails with visible addresses, no-reply addresses and attachments over 20 MB.

  • Remind me

    A mail comes back at the time you pick, on the board and as a notification.

  • Unsubscribe in one click

    Where the newsletter offers it, in one click, without hunting for the link in the mail.

  • Snippets

    Recurring replies with placeholders for name, date and company.

  • Signature by recipient

    Signatures of their own for certain domains or addresses, switched as you write.

  • Send one by one

    A group mail goes out as a separate mail to each recipient, with a personal greeting if you like.

  • Writing with AIAI

    A draft from a few notes, with the context you choose.

  • TranslateAI

    The bar above a mail in another language translates it, only after your click.

For staying organised
  • BoardFree

    Mail and notes as cards in columns. One board is free, with Pro as many as you like.

  • Tasks

    From Nextcloud or another CalDAV server, and with the companion add-on from Thunderbird too, ticked off on the board.

  • SearchFree

    Best matches first, actions on each result. With Pro, in Paperless too.

  • NotesFree

    Markdown, linked to people and mail. With Pro, synced with Nextcloud, Obsidian or Joplin.

  • Dashboard

    The day's events, mail, tasks and notes on one page.

  • SummariseAI

    One or more mails in brief, with the events and tasks in them.

  • Person page

    Mail, cards and notes with one contact in a single timeline.

  • Assistant

    Reminds you of replies still open and suggests rules for filing.

  • Command palette

    One shortcut for any folder, contact or action.

  • Read later

    Collect articles from mail and feeds, in Glassbird, wallabag or Readeck.

  • Contacts from signatures

    Phone, address and company from the signature into your address book, only what you tick. Off by default.

For advanced users
  • AI on your computer

    With Ollama or LM Studio, no text leaves your computer. Or a provider with your own key.

  • My styleAI

    Drafts learn from your examples and corrections and sound like you.

  • Paperless and Nextcloud

    Attachments into your archive in one click, documents from your files straight into a mail.

  • Sender signature

    Shows in the header and in Conversations whether a mail really was signed by the domain it names (DKIM), also for mail Proton Bridge changes. Off by default.

  • QR and barcodes

    A link, contact, Wi‑Fi network or GiroCode as a QR code right in the mail.

  • Writing aidCompanion add-on

    Spelling, grammar and style with your own LanguageTool server.

  • Online meetingsCompanion add-on

    Your meeting link for Zoom, Teams or Meet, a new room for Jitsi and Nextcloud Talk, in one click in the event.

  • AutomationsCompanion add-on

    Assistants such as Claude work with your mail, boards and notes through a local MCP server. Changes need a switch of their own.

  • Browser extensionBetaCompanion add-on

    For Firefox and Chrome: pages for later, onto the board or as a note.

Privacy

Your mail stays with you.

Stored on your computer.

Boards, notes and settings live in Thunderbird on your computer. Glassbird Pro sends no usage data, with no analytics and no ads.

Your AI, if you want it.

The AI features are off until you set up a model. With Ollama or LM Studio, every text stays on your computer. With an online provider, Pro always shows where a text is going and asks before documents or your style profile go there.

No account.

No sign-up, no login. Pro activates your licence key with our activation service and has it checked there about every 30 days; only the licence ID, days and an identifier per device are stored. Apart from this check and looking for updates, Pro only talks to services you set up or switch on yourself.

All the details in the privacy policy

Pricing

Pay once. Keep it.

Glassbird Pro

€29.99 one-off

Coming soon to addons.thunderbird.net.

  • Board, search and notes stay free, also after the trial.
  • Try everything else for 30 days, once per Thunderbird profile, with no account.
  • One licence covers you on your own computers, in up to five Thunderbird profiles at a time.
  • Twelve months of updates included. After that, your version keeps working with the Thunderbird versions it supports; renewing for another twelve months costs €15. A renewal unlocks new features in versions released after that.
  • Installed like any add-on, as a file from glassbird.app; Thunderbird then fetches updates by itself.

Phone and CRM in Thunderbird come with Glassbird Business, which is still being built. Compare plans ›

System requirements

What you need.

Thunderbird
Thunderbird for desktop computers from version 153, on Windows, Linux or a Mac, and internet access to activate the licence key and have it checked at least every 90 days. Thunderbird for smartphones and tablets is not supported.
Companion add-on
For the marked features and the trial, the free Glassbird Pro Experiments, currently for Thunderbird 153 to 161. Mozilla plans to restrict such interfaces in the regularly updated Thunderbird release, currently not before summer 2027. Thunderbird ESR and Betterbird are not affected as things stand. It uses interfaces that Thunderbird does not yet officially offer to add-ons, which is why Thunderbird mentions full access when you install it. In the view of the Conversations add-on, the bar above the mail appears only with it.
Glassbird look
Not needed. Pro runs without it; only the appearance settings need the free theme. See Glassbird ›
AI
Optional. Run locally with Ollama or LM Studio, the AI costs nothing but needs a capable computer. With a provider and your own key, you pay them for what you use; Pro shows the tokens per draft and per month, and with your model's prices the cost too. Glassbird earns nothing from it. Only the features marked AI need a model.
Beta
Every feature above is there already; some will still change. Pro is developed mainly on the Mac; on Windows and Linux it has not been checked as thoroughly yet. Help and reporting a problem ›

Try everything for 30 days.

Coming soon to addons.thunderbird.net.

Setup and help