How does link tracking domain reputation affect deliverability?

Your tracking links are in every email you send. When spam filters scan your message, they don't just evaluate your sending domain. They evaluate every URL in the body. If your tracking domain has a bad reputation, your emails pay the price regardless of how clean your content is.

This is a real problem with shared tracking domains. Many ESPs use a single tracking domain across all their customers. If another sender on that shared domain runs a spam campaign, the tracking domain can land on blocklists like Spamhaus DBL or Google Safe Browsing. Your perfectly legitimate emails now contain links to a blocklisted domain. Filters flag them. Recipients see warnings. Clicks drop.

So The solution most serious senders move to eventually is a custom tracking domain: a subdomain you own, like click.yourdomain.com, configured as a CNAME in your DNS pointing to your ESP's tracking servers. Your reputation is your own. A neighbor's bad behavior doesn't contaminate your links.

Keep that custom tracking domain clean. Don't use it for anything except tracking. Monitor it with our free Blocklist Checker occasionally, because tracking domains can end up on blocklists if your list hygiene slips. High complaint rates or spam trap hits from your campaigns will eventually touch your tracking domain's reputation too.

If you're on a shared tracking domain and can't move to a custom one yet, it's worth checking whether your ESP lets you at least verify which shared domain they use, so you can monitor its domain reputation and know if problems are coming from that direction.