Installation

Two steps: install the add-on, then launch it from Sheets.

Install MailG

1. Open the MailG listing on Google Workspace Marketplace.
2. Click Install.
3. Choose the Google account that should own the install.
4. Review the permissions and click Allow.

Installation usually finishes in under 15 seconds. You should see a confirmation that the add-on was installed.

Checklist — what you should see

Launch MailG in Google Sheets

1. Open Google Sheets (refresh if Sheets was already open).
2. Wait a few seconds for Extensions to load (often ~10–15 seconds).
3. Go to Extensions → MailG for Gmail → 🚀 Start.

The start dialog opens as a sidebar/modal over the sheet. If the sheet has no emails yet, you will see the empty-state prompt (add a column or Fill with mock data) — see Start dialog tour.

Later you can run Extensions → MailG for Gmail → 🔄 Refresh Tracking to sync open statuses without opening the full dialog.

Installation issues

These are common Google Workspace quirks, not MailG bugs:

I never see the “installed successfully” popup

This often happens when multiple Google accounts are signed in and the install did not use the account you expected.

Workaround: open a private/incognito window, sign in with only the target account, then install again from the Marketplace.

MailG does not appear under Extensions

1. Refresh the spreadsheet.
2. Wait about 10–15 seconds for add-ons to load.
3. Confirm you are in the same Google account that installed MailG.
4. Try another spreadsheet or clear the browser cache if it is still missing.

Self-hosted / custom deployments

Marketplace installs are preconfigured. If you deploy MailG yourself, set Apps Script script properties:

The add-on cannot reach localhost from Google’s servers — use a tunnel (Cloudflare Tunnel, ngrok, etc.) for local testing.

Next

Continue with the mail merge tutorial.