Email tracking

Mail Merge tells you who opened your emails and who clicked a link in them. The result lands in your spreadsheet, in the campaign details, and in the account-wide Analytics and Activity screens.

Turn tracking on

In the campaign builder, switch Track opens on before sending. In Google Sheets it is the double-check icon in the bottom bar; in the web app it is the switch in the Settings column.

The Track opens switch in the builder settings

Tracking inserts an invisible pixel in each email and, on the Personal and Professional plans, rewrites links so that clicks pass through Mail Merge. Open tracking is part of every plan; click tracking is a Personal plan feature (included in Professional), so a free account gets Read but never Clicked. Tracking is off by default; follow-up sequences turn it on automatically.

What you see in the sheet

The status column updates as recipients react:

The status column with Sent, Read, Clicked and Unsubscribed rows

Sent becomes Read when the recipient opens the email.
Read becomes Clicked when the recipient clicks a link in it (paid plans; links are not tracked on the free plan).
Either becomes Unsubscribed when the recipient uses the unsubscribe link.
On a paid plan, Sent, Read or Clicked becomes Replied when the recipient answers, and Bounced when the address could not be delivered to. See Replies and bounces below.

Statuses are refreshed every time you open Mail Merge from the sheet. To refresh without opening anything, use Extensions → Mail Merge for Gmail → 🔄 Refresh tracking. It updates the tab you are looking at.

Replies and bounces

Opens and clicks come from the tracking pixel and link; replies and bounces come from your Gmail account itself, so they need no tracking to be on. For 14 days after a campaign finishes, Mail Merge checks its sent threads, often at first and less often as the campaign ages (every 30 minutes for the first 6 hours, then every 2 hours for two days, every 12 hours until day 7, then once a day): a thread with an answer from the recipient marks the row Replied, a thread whose only answer is a mailer-daemon or postmaster delivery failure marks it Bounced. Both land in the status column of your sheet, in the campaign details and in Analytics (reply and bounce rates), and a bounced address is flagged in Contacts so you can clean your list.

Good to know:

It is a Personal plan feature (included in Professional). A free account keeps Sent / Read.
Only replies in the same Gmail thread count. A recipient who writes a brand-new email is not detected.
Detection reads message headers only, through the Gmail permission you granted when connecting Mail Merge. If you connected before this permission existed, reconnect from Settings in the web app; until then the check is skipped silently.
A reply more than 14 days after the campaign finished is not picked up, and a late reply can take up to a day to show (the checks get sparser as the campaign ages).
Replied and Bounced are final: a later open or click never changes them back to Read or Clicked.

What you see in the web app

Open the campaign in Campaigns for the Sent, Opened, Clicked and Unsubscribed counts with their rates, and the status of every recipient.

A campaign’s engagement cards and per-recipient statuses

Activity lists every open, click and unsubscribe across campaigns, newest first. Analytics aggregates them over any period, with open and click rates and your top links.

How reliable is it?

An open is detected when the mail client loads the tracking pixel. Clients that block remote images (and some privacy features that preload every image) make opens under- or over-counted. Clicks are exact.
Opens are counted once per recipient per campaign; several opens by the same person still show as Read.
Every email shows Read seconds after sending, or a recipient shows Read before they could have opened it: corporate security scanners and link-checking proxies open images and links on the recipient’s behalf. Treat opens at corporate domains as an upper bound; clicks are not affected in the same way.
Tracking must be on when you send. It cannot be turned on for a campaign already sent.