Privacy Policy

1. The short version

Mail Warmer is a free, open-source Chrome extension that keeps your inboxes active. It never reads, opens, or sends from your inbox. Your email addresses and profile details stay on your device — they are only ever typed into the newsletter signup forms you choose, exactly as you would do by hand. There is no account to create and no payment to make.

2. What stays on your device

Everything you enter is stored locally in your browser, visible only to the extension:

• The email addresses you add and their labels
• Your optional profile (name, location, and similar fields used to fill signup forms)
• Your newsletter list and any custom newsletters you add
• Your signup history and activity log
• The results of the optional cookie warm-up

None of this is sent to us or to anyone else.

3. The only things that touch the network

Two small, anonymous exchanges happen — and neither involves your personal data:

• Newsletter list — the extension downloads the curated newsletter list so it stays up to date. This is a read-only request; nothing about you is sent.
• Anonymous run tally — after a run, the extension sends a count of how many signups succeeded or failed per newsletter, tied to a random installation ID. This ID is not linked to you or your emails in any way.

4. What we never collect

We do not collect:

• Your email addresses or their contents
• Your profile details (name, address, phone, etc.)
• Your browsing history or the pages you visit
• Keystrokes, screenshots, or screen recordings
• Payment or financial information (there are no payments)
• Any personally identifiable information

5. How the anonymous tally is used

The only reason for the run tally is to understand which newsletters tend to work and which break, so the curated list can be kept healthy. It is aggregate, anonymous, and never sold or shared with third parties.

6. Cookie warm-up

The optional Cookies tab visits a few well-known websites in the background and accepts their cookie banners, then reads back the cookies those visits left in your browser. This all happens locally and is shown only to you — the captured cookies are never sent anywhere.

7. Third-party services

When Mail Warmer subscribes you to a newsletter, you are signing up with that newsletter's own provider (for example a Substack publication or another email service). Those providers have their own privacy policies governing the address you submit, just as they would for a signup you did yourself.

8. Your control

Because your data lives on your device, you can:

• Edit or delete any email or profile field at any time
• Clear your history and log
• Remove the extension to erase everything it stored

9. Children's privacy

Mail Warmer is not intended for children under 13, and we do not knowingly collect any information from them.

10. Changes to this policy

We may update this Privacy Policy from time to time. Any changes will be posted on this page with an updated date above.

11. Contact

Mail Warmer is open source. Questions about privacy are best raised in the open, so anyone can see the answer — please open an issue on GitHub.