MergelineHow do I track if an email was opened in Gmail?
Updated October 29, 2026
Open tracking needs a third-party tool that hides a tiny image, called a tracking pixel, in each email. Google’s mail merge help page does not mention open tracking. Many add-ons, including GMass, YAMM and Mailmeteor, add pixels. Opens are unreliable, though: Apple Mail loads images in advance and inflates them. Replies are the number that really tells you something.
How open tracking works
The tool adds a small, invisible image with a unique address to each email. When the email client loads that image, the tool’s server logs an “open”. That is all an open is: an image request.
Since Apple Mail Privacy Protection, Apple’s mail app can load those images on its own, before the person reads anything. Mailchimp’s own help page warns that open numbers are unreliable for people who use it.
The hidden cost
- Practitioners report that Gmail can show a banner on emails with tracking images, next to a one-click spam report. This comes from users, not from Google, but it is a common reason cold emailers turn tracking off.
- Pixels send data about your readers to a third party, which some people and companies do not want.
- Click tracking rewrites your links through another domain, which can look suspicious.
What Mergeline does instead
Mergeline adds no tracking pixels and no link redirects. The emails it sends look exactly like ones you typed. Instead of opens, it reports what matters: who replied, who bounced and who asked to unsubscribe, found by checking your own Gmail.
If you want to test which subject works better, compare reply rates. Mergeline Pro’s A/B test does just that. More in do tracking pixels hurt deliverability.
Signals you can trust
A reply is proof someone read the email. A bounce is proof the address is wrong. An unsubscribe is a clear no. Everything else is a guess.
If you still want opens
Use tracking only for mail to people who know you, and do not treat a missing open as a no. Follow up based on replies.
Read the full guide: Open tracking pixels
Related answers
Sources
- Google: Send personalized emails with mail merge in Gmail
- Mailchimp: Apple Mail Privacy Protection FAQ
- r/coldemail: does open tracking harm deliverability?
Facts checked October 29, 2026. Google and other vendors change their limits and prices, so check the source before you rely on a number.
Mergeline does this from your own Gmail. Free for 60 emails a day with merge tags and no branding. Pro is $12 a month or $99 a year for follow-ups, scheduling and attachments.