What is a tracking domain?

A tracking domain is a custom domain you configure to replace generic ESP tracking links in your emails. When you set one up, every click and open pixel in your campaigns gets rewritten to use your brand's domain instead of your ESP's default tracking URL.

But Here's what that looks like in practice. Without a tracking domain, a link in your email might look like this: https://mailchimp.us20.list-manage.com/track/click?u=abc123&id=xyz789. With a tracking domain, the same link becomes: https://clicks.yourbrand.com/t/abc123. The first one screams "generic mass email." The second one looks like it belongs to you.

Why does this matter? Mailbox providers and spam filters look at every link in your email. If the links point to a domain that doesn't match your brand, it raises a red flag. Generic tracking links look like what phishing emails use (links that promise one thing but go somewhere else). A branded tracking domain proves you control both the From address and the links inside. That alignment improves deliverability.

Setting up a tracking domain means creating a CNAME record in your DNS that points to your ESP's tracking infrastructure. For example, you might create clicks.deepcurrent.io as a CNAME pointing to your ESP's tracking server. Your ESP's documentation will give you the exact value to use. Once it's set up, your ESP automatically rewrites all links to use your custom domain.

But Not every ESP calls this feature the same thing. Mailchimp calls it a "tracking domain," SendGrid calls it a "branded link," and Klaviyo calls it a "click tracking domain." Same concept, different names.

One common mistake: using the exact same subdomain for both your sending domain and your tracking domain. If you send from mail.yourbrand.com, don't also use mail.yourbrand.com for tracking. Use something like clicks.yourbrand.com or track.yourbrand.com instead. This keeps your authentication records clean and makes troubleshooting easier.

And If you're not sure whether you have a tracking domain set up, click a link in one of your own emails and look at the URL in your browser's address bar before the page loads. If it's your ESP's domain, you don't have one. If it's your brand's domain, you do. You can also check with our Email Header Analyzer to see what domains are actually used in your sent mail.