A custom tracking domain lets the open, click, and unsubscribe links inside your cold emails use your own domain — for example track.yourdomain.com — instead of the shared WarmySender domain. It's a simple, one-time DNS change that makes your emails look more trustworthy to inbox providers and keeps your brand on every link. This guide covers what it is, why it improves deliverability, the exact CNAME step, how to verify it, and the safety net that keeps your campaigns sending even if the domain is ever removed or breaks.
This is part of the WarmySender 4-pillar platform — Cold Emailing, Email Warmup, LinkedIn Outreach, and Multichannel. A custom tracking domain applies to your cold email campaigns.
Every cold email you send can include invisible open tracking, click tracking, and a one-click unsubscribe link. Those links have to point to a web address. By default, that web address sits on a domain shared by many WarmySender customers. A custom tracking domain swaps in a small subdomain of your domain — such as track.acme.com — so the links in your emails belong to the same domain you send from.
Mailbox providers like Gmail and Outlook pay attention to whether the links inside an email line up with the domain that sent it. If you send from acme.com but your tracking links live on a shared, unrelated domain, that mismatch is a small negative signal that can nudge you toward spam. When your tracking links are on track.acme.com — clearly part of your own domain — everything matches, which looks more legitimate and helps your emails land in the inbox. As a bonus, your recipients only ever see your brand in the links, never a shared domain.
Setting this up is a single DNS record. In WarmySender:
track subdomain of your sending domain — e.g. track.yourdomain.com.track.warmysender.com.track (just the subdomain part — most DNS providers fill in the rest of your domain automatically)track.warmysender.com3600)Back in Settings › Tracking Domains, click Verify next to your domain. WarmySender confirms your domain is genuinely live from end to end — that the CNAME points to the right place and that your domain securely serves your tracking links — not just that a DNS record exists somewhere. When it succeeds, the status turns to Verified, and from that moment your campaigns automatically use your domain for open, click, and unsubscribe links. If it isn't ready yet, you'll see Pending or Error — double-check the CNAME name and target, give DNS a little more time, and click Verify again.
Status meanings:
This is the important part. Once your domain is Verified, WarmySender keeps quietly checking that it stays healthy. If you remove the custom domain, or its DNS is later changed or deleted so it stops working, WarmySender automatically falls back to our default domain for your tracking links and your campaigns keep sending without a hitch. A broken or removed tracking domain can never stop your emails from going out — the worst case is simply that your tracking links temporarily use our default domain again until you fix yours.
Say you send from [email protected] and want branded tracking:
track.acme.com.track.warmysender.com.track, Value = track.warmysender.com, TTL Automatic.track.acme.com — matching your sending domain. If you ever delete that CNAME, campaigns quietly revert to the default domain and keep sending.track.acme.com if you send from @acme.com — so everything lines up.No. It's an optional upgrade for deliverability and branding. Without one, your open, click, and unsubscribe links use our shared default domain, which works fine.
Exactly one CNAME record: Name/Host = track (or whatever subdomain you chose), Value/Target = track.warmysender.com, TTL Automatic or 3600. Nothing else.
DNS can take up to 48 hours to spread, though it's usually much faster. Confirm the Name is just the subdomain (track) and the Value is exactly track.warmysender.com with no extra characters, then click Verify again.
Your campaigns keep sending. WarmySender automatically falls back to our default domain for tracking links the moment a custom domain is removed or stops working, so a broken tracking domain can never interrupt your sending.
No. It only affects links in emails sent from that point forward. Your existing stats stay exactly as they are.
Yes. Once a domain is Verified in your workspace, all of that workspace's campaigns use it automatically.
Email us at [email protected] with the domain you're setting up. For instant answers, you can also open warmysender.com/documentation, click "Copy Prompt to Clipboard," and paste it into an AI assistant like Claude or ChatGPT along with your question.
Related: Custom Tracking Domains overview · Email Deliverability (SPF, DKIM, DMARC) · See which recipients opened your emails.