Open & click tracking

Tracking tells you whether recipients opened your emails and clicked the links in them. It's optional and configured per domain.

How it works

When tracking is enabled for a domain, SendGrail rewrites outgoing HTML just before the message is sent:

• Open tracking injects a tiny invisible image (a 1×1 pixel) at the end of the HTML body. When a mail client loads that image, SendGrail records an open.
• Click tracking rewrites each link so it points at SendGrail first. When the recipient clicks, SendGrail records the click and immediately redirects them to the original URL.

Both the pixel and the redirect are served from a tracking subdomain that belongs to your domain — for example links.example.com — so links in your mail stay on your own brand, not a third-party host.

Plain-text bodies are never modified. Open and click events appear on each message's timeline in the dashboard's Emails view.

Enabling tracking for a domain

Tracking is set up from a verified domain's detail page in the dashboard:

1. Open the domain and start the tracking setup.
2. Choose a tracking subdomain (e.g. links.example.com).
3. Add the CNAME record SendGrail shows you at your DNS provider.
4. Verify it.

Once the tracking subdomain is verified, new messages from that domain are tracked. Existing, already-sent messages are not affected.

TIP

The tracking subdomain is separate from the DKIM / MAIL FROM records used for domain verification. It's one additional CNAME.

Reading the results

Open and click events show on the message timeline alongside sent, delivered and so on. Treat them as engagement signals, not exact counts, because of the caveats below.

Tracking is not exact

• Apple Mail Privacy Protection pre-loads images for many recipients, so some "opens" are Apple's servers, not the person. Open rates skew high.
• Security scanners at corporate mail gateways fetch images and follow links before the recipient ever sees the message, producing opens and clicks nobody made.
• Recipients who read mail with images disabled register no open even if they read every word.

Open and click tracking is industry-standard and useful in aggregate — just don't treat a single open or click as proof of a specific human action.

Not delivered over webhooks

Open and click events are currently visible only in the dashboard. They are not sent to webhooks — webhook event types cover the delivery lifecycle (sent, delivered, bounced, complained, failed, rejected, suppressed) but not engagement.

Disabling tracking

Turn tracking off from the domain's detail page. Messages sent afterward are no longer modified. You can leave the tracking-subdomain CNAME in place in case you re-enable later, or remove it at your DNS provider.