Download
Install MailSignals in Chrome or Edge.
MailSignals is not on the Chrome Web Store yet, so for now you add it yourself: one download, one switch, one folder. It takes a couple of minutes. Then you sign it in with Google, using the account you use on the dashboard, and that is the whole connection. There is no key or code to copy.
MailSignals 1.1.1
One file for Chrome and Microsoft Edge on a computer. It runs in Gmail in the browser; on a phone, use the dashboard instead.
- Version
- 1.1.1
- File
mailsignals-1.1.1.zip, 530 KB- Extension ID
ghmgnmmdmbaljckigkobnebgmnembkfd- SHA-256
945f8d39aaa10feb18c306d1dbd1200436d6700ffe9df7c1913e61325ce0bef0
Install it
The same steps in both browsers. Only the address of the extensions page and the place of one switch differ.
Download and unzip it
Download
mailsignals-1.1.1.zipand unzip it. Put the folder somewhere it can stay, such as your Documents folder: the browser runs MailSignals from that folder, so moving or deleting it removes the extension.Open the extensions page
Type
chrome://extensionsinto Chrome's address bar, oredge://extensionsinto Edge's, and press Enter.Switch on Developer mode
The switch is at the top right of the page in Chrome, and at the bottom of the menu on the left in Edge. It lets the browser load an extension from a folder. Leave it on: switching it off can disable extensions added this way.
Load the folder
Click Load unpacked and choose the folder you unzipped: the one with
manifest.jsondirectly inside it. MailSignals appears in the list with the IDghmgnmmdmbaljckigkobnebgmnembkfd. Every copy from this page has that ID, in Chrome and in Edge.Sign in with Google
A MailSignals tab opens by itself with a short checklist. Click Sign in with Google and choose the Google account you use on the dashboard, ideally the Gmail account you send from. You can also sign in from the MailSignals button in the toolbar; pin it from the puzzle-piece menu to keep it in view.
Reload Gmail
Any Gmail tab that was already open shows a banner asking to be reloaded. Reload it: a tab opened before the install has no MailSignals in it, so nothing sent from it is tracked.
Stop your own reads from counting
In Gmail, open Settings, then See all settings, and under Images choose Ask before displaying external images. Do it on every device you read mail on. It is the one change that keeps your own phone from loading the tracking image and being counted as a reader. Why it matters
Send a test
Write to someone else: mail where every recipient is one of your own addresses is never tracked. A grey ✓ appears on the message in your Sent folder, and becomes a green ✓✓ once it has been opened. The dashboard shows the whole timeline, with the reason behind each verdict.
How the extension and the dashboard work together
They are two views of one account, joined by the Google account you sign in with. Use the same one in both and they share everything.
| The extension, in Gmail | The dashboard, app.mailsignals.io | |
|---|---|---|
| What it is for | Tracking as you send, and what has happened since, where you read mail | The whole history, and the reason behind every verdict |
| What it does | Adds the pixel and signed links when you send, draws the checkmarks, notices replies and bounces, and shows notifications | Lists your emails, contacts, links and alerts, and holds every setting, the Gmail accounts you allow, export and deletion |
| How it connects | Sign in with Google, in the extension | Sign in with Google, on the dashboard |
Settings follow you
A setting changed in the extension reaches the dashboard straight away. One changed on the dashboard reaches the extension on its next check: within a minute while Gmail is open, within five minutes otherwise.
A second Gmail account
Only the account you signed in with is tracked automatically. Send from another Gmail account in the same browser and the dashboard lists it under Settings → Gmail accounts; nothing sent from it is tracked until you approve it there.
No key for the extension
The agent keys on the dashboard are for software that sends mail without a browser, such as an AI agent. The extension never needs one. The MCP server for agents
For AI agents: the MCP server
Mail an assistant sends through the Gmail API never passes through your browser, so the extension cannot track it. This server lets the agent ask MailSignals to prepare the message instead.
Create a key in the dashboard under Settings → Agent keys, then add the block on the right to your MCP client; Copy MCP config on the same screen fills your key in. npx fetches the server from this site and runs it: one self-contained file, nothing to install, Node.js 22 or later. How the agent API works
- Version
- 1.0.0
- File
- mailsignals-mcp.tgz, 164 KB — always the newest version
- SHA-256
5c56968b0df72327b101315c3718593e64e3157a4f5d25a852b4732a129c7aea
{
"mcpServers": {
"mailsignals": {
"command": "npx",
"args": [
"-y",
"https://mailsignals.io/download/mailsignals-mcp.tgz"
],
"env": {
"MAILSIGNALS_API": "https://app.mailsignals.io/api",
"MAILSIGNALS_AGENT_KEY": "msk_…"
}
}
}
}Updating
A copy installed from this page does not update itself.
When this page offers a newer version than the one under MailSignals on your extensions page, download it, unzip it, and choose the new folder with Load unpacked. The browser replaces the old version in place: same extension, same settings, still signed in. Then delete the old folder, and reload your Gmail tabs when the banner asks.
The newest version is 1.1.1.
Removing it
Removing the extension does not delete your account.
On the extensions page, click Remove under MailSignals. The browser deletes everything the extension kept on your computer. Your history stays in your account until you delete it from the dashboard, under Settings → Delete everything.
If something does not work
Load unpacked says the manifest file is missing
You chose the folder one level up. Choose the folder that has manifest.json directly inside it.
Sign-in fails, or the ID is not ghmgnmmdmbaljckigkobnebgmnembkfd
The copy you loaded is not one from this page. Remove it, download the zip again, and load the new folder.
Nothing appears in Gmail
Reload the Gmail tab. Then check on the extensions page that MailSignals is switched on, and Developer mode with it.
A message went out untracked
The compose window says why before you send: every recipient is one of your own addresses, a recipient is on your do-not-track list, the Gmail account you are sending from is not approved yet, or the tab needs reloading after an update. You can also switch tracking off for one message from the compose toolbar.
Installed? Open your dashboard.
Sign in with the same Google account you used in the extension, and every email you send from Gmail shows up there with the reason behind each verdict.