Tracking Domains, Redirects, and Technical Mistakes That Hurt Inboxing
Tracking domains and redirects are where cold email infrastructure silently breaks. Here are the most common technical mistakes and exactly how to fix them.
Authentication gets the attention, but tracking domains and redirects cause an enormous amount of quiet deliverability damage. These are configuration issues that don't show obvious errors — they just gradually hurt your placement until campaigns stop working.
Tracking domain mistakes
Mistake 1: Proxied through Cloudflare
This is the most common tracking domain mistake. When you set up a tracking domain CNAME in Cloudflare with the proxy enabled (orange cloud icon), Cloudflare intercepts the traffic before it reaches your ESP's tracking server. This breaks click and open tracking — and some ESPs will throw errors or disable tracking for the domain.
Fix: In Cloudflare, click the orange cloud next to your tracking domain CNAME. It should turn grey (DNS Only). This disables proxying and lets traffic flow directly to your ESP. Verify with the tracking domain checker.
Mistake 2: Tracking on the same domain as sending
Using a subdomain of your sending domain (like track.yoursendingdomain.com) for tracking links means that click tracking behavior is associated with your sending domain's reputation. Bad tracking signals affect sending reputation.
Fix: Purchase a completely separate domain (not a subdomain) for tracking. Something generic works fine — the domain doesn't need to match your brand. Set it up with the correct CNAME for your ESP.
Mistake 3: No SSL on tracking domain
If your tracking domain doesn't have a valid SSL certificate, tracking links will be http:// rather than https://. Many email clients and security tools flag HTTP links in email as suspicious. Some ESPs will also show errors for invalid SSL on tracking domains.
Fix: Ensure your tracking domain has a valid SSL certificate. This is usually handled automatically by your ESP when the CNAME is correctly configured. Verify with the tracking domain checker.
Mistake 4: Tracking domain sharing reputation with problematic domain
If you're using the same tracking domain across many different sending domains — especially across different clients — a reputation problem with one client's sends can affect tracking for all of them.
Fix: Ideally, each client has their own tracking domain. At minimum, high-risk clients (aggressive volume, questionable list quality) should be on their own tracking infrastructure.
Redirect mistakes
Mistake 5: Sending domain doesn't redirect at all
A domain that doesn't respond to HTTP requests looks like it's not a real website. Spam filters use this as a negative signal. Your sending domain should redirect to something — even a simple landing page is fine.
Fix: Set up a redirect from your sending domain to your main business website, or create a simple landing page. Check that the redirect works with the redirect checker.
Mistake 6: HTTP doesn't redirect to HTTPS
All email links should resolve over HTTPS. If your domain doesn't force HTTPS, some links in your emails may be flagged. Also a basic hygiene issue that affects trust signals.
Fix: Ensure both http://yourdomain.com and http://www.yourdomain.com redirect to https://yourdomain.com. Verify with the redirect checker.
Mistake 7: Redirect chains
Multiple redirects before reaching the final destination slow down link resolution and can look suspicious to security tools. Email security scanners that follow redirect chains may flag long chains as suspicious.
Fix: Ensure your redirect goes directly from http to https without intermediate redirects. A chain like http → http://www → https://www → https is unnecessarily long and should be collapsed.
Mistake 8: Redirect pointing to a broken or parked page
Sending domains that redirect to parked domain pages or 404 pages signal that the domain was purchased and configured without a real business purpose — classic spam infrastructure behavior.
Fix: Ensure the destination of your redirect is a real, working page. A simple redirect to your business homepage is sufficient.
Running the full technical check
The tracking domain checker and redirect checker handle most of these in one pass. For a comprehensive technical audit, work through the launch checklist which includes all of these elements with links to each specific tool.
Run the checks first
Before replacing anything, run a free inbox placement test. You might find the issue is DNS, not the domain — and save yourself a week of unnecessary work.