Installation

Mail Merge for Gmail is a Google Workspace add-on. You install it once from the Marketplace, and it then appears in Google Sheets (the Extensions menu), in Gmail (the right-hand side panel) and in Google Docs (to import a document as a template). This page walks through the installation and shows where everything lives.

1. Install the add-on

Open Mail Merge for Gmail on the Google Workspace Marketplace and click Install.

Google then asks you to confirm two things:

1. Which Google account to install the add-on on. Pick the account you send email from.
2. The permissions the add-on needs: sending email on your behalf, reading the spreadsheet you run a campaign from, and downloading the files you attach. Click Continue to allow them. Every permission is explained on Permissions & your data.

After a few seconds Google confirms that the add-on has been added to your Docs, Sheets and Gmail sidebar.

Caution

Grant all the permissions in one go. Since late 2025 Google lets you skip individual permissions on the consent screen, and an add-on installed with a partial grant cannot always ask again for the missing ones. If you skipped one, see Fixing a partial authorization below.

2. Open Mail Merge in Google Sheets

Open a spreadsheet (if one was already open, refresh the page so the new add-on loads), then go to Extensions → Mail Merge for Gmail.

Add-ons take 10 to 15 seconds to load after a spreadsheet opens, so the menu may appear a moment after the page.

The Mail Merge menu

Every item opens Mail Merge in a window on top of your spreadsheet, except the last three:

Item	What it does
▶️ New campaign	Opens the campaign builder with the current sheet already loaded as the recipient list. This is where you write and send. See the tutorial.
📨 Campaigns	Every campaign you have sent or scheduled, with live progress. See Campaigns.
📝 Templates	Your saved email templates, the template gallery, AI generation and Google Docs import. See Templates.
👥 Contacts	Everyone your campaigns have emailed, your contact lists, unsubscribers and blocklist. See Contacts.
🔥 Warm up	Build your sender reputation automatically, and check any address with the reputation checker. See Email warm-up.
🤝 Team	Buy seats and share your subscription with colleagues. See Team seats.
⚙️ Settings	Sending speed (delay between emails) and push notifications. See Settings.
💳 Billing	Opens your subscription in a new browser tab: invoices, payment method, plan changes. See Pricing & subscription.
📖 Support	Opens this documentation in a new tab.
🔄 Refresh tracking	Pulls the latest open, click and unsubscribe statuses into the current sheet. See Email tracking.

Tip

The window that opens is the same application as the Mail Merge web app at merge.email/app. Anything you do in one place shows up in the other, and the only difference is that the builder opened from Sheets already knows which spreadsheet you are working in.

3. Mail Merge in Gmail

In Gmail, Mail Merge sits in the right-hand side panel. Click its icon to open a small card with shortcuts to the main screens.

• Start mail merge walks you through the first campaign and creates a new spreadsheet for you.
• Open web app opens Mail Merge in a full browser tab.
• Explore features opens the feature list in this documentation.
• Manage subscription opens your plan and billing details.

The Gmail card is a launcher only. Campaigns are written and sent from Google Sheets or from the web app.

Installation issues

The add-on does not seem to install, or you never see the “installed” confirmation. This happens when you are signed in to several Google accounts and the Marketplace installs on a different one than you expect. Open a private browser window, sign in with the account you want, then install again.

After installation, Mail Merge is not visible in the Extensions menu. Refresh the Google Sheets page and wait about ten seconds. Add-ons load after the spreadsheet itself.

Mail Merge opens but shows “We need you to re-authorize Mail Merge”. The add-on is installed but is missing a permission. Click Re-authorize Mail Merge, approve every permission on Google’s screen, then click Reload addon.

Fixing a partial authorization

If re-authorizing does not help, Google is remembering a partial grant. Reset it:

1. Open myaccount.google.com/connections, find Mail Merge, and choose Delete all connections you have with Mail Merge.
2. Close the Mail Merge window and refresh the spreadsheet.
3. Open Extensions → Mail Merge for Gmail → New campaign again and grant all the permissions when asked.

If that still fails, uninstall Mail Merge from the Marketplace (the Install button becomes Uninstall once it is installed), then install it again.

The same checks exist in Gmail: when the side panel shows Permission required, click Grant permission, approve everything, then Check again.