Tracking domain checker: is the custom tracking domain for Instantly, Smartlead, lemlist or Apollo set up?
In short: For each sending domain, looks up the tracking subdomain the tool uses (inst for Instantly, emailtracking for Smartlead, your own for lemlist or Apollo), checks the CNAME points to the tool's target, that HTTPS answers, and whether the domain is on a domain blocklist. A verdict and the fix per domain. Limit: Up to 10 domains a run, because of the lookup rate limits.
Paste up to 10 sending domains and pick the tool. Each tracking host (inst.yourdomain for Instantly, emailtracking.yourdomain for Smartlead, your own subdomain for lemlist or Apollo) is looked up: the CNAME must reach the tool's target, HTTPS must answer, and the domain is checked against domain blocklists, since every tracked link carries it. Each domain gets a verdict and a fix.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. See pricing
Instantly's guide fixes the subdomain as inst.
Sample result
inst.getacme.example has no CNAME: add host inst pointing to prox.itrackly.com.
- Tracking host
- inst.getacme.example
- Expected
- prox.itrackly.com
- Tool
- Instantly
What this means for you
Until it resolves, Instantly can't verify it and tracked links keep the shared domain.
- Up to 10 sending domains
- Instantly, Smartlead, lemlist, Apollo
- CNAME, HTTPS and blocklists
- The fix for each domain
- CNAME
- HTTPS
- DBL
By SimpleVerifier Team · Last updated
Tracking domains are set. What's next before the campaign?
- Check SPF, DKIM and DMARC on the same domains with the cold email domain checker.
- Upload the lead list at /verify for a live mailbox check; bounces hurt the domain the tracking subdomain sits under. The first 100 email checks are free with a Google sign-in, no card.
- Import the valid leads into the campaign.
How do I check that a custom tracking domain is working?
- Paste your sending domains, one per line (up to 10 a run).
- Pick the sending tool. Instantly's subdomain is fixed as inst; for Smartlead and lemlist change the subdomain if you used another; for Apollo or another tool, paste the CNAME target your tool shows.
- Press Check tracking domains. Each domain gets Ready, Not set up, Points elsewhere, No CNAME visible (usually a Cloudflare proxy), HTTPS problem or Domain blocklisted.
- Fix what it says, wait for DNS to update, run it again, then run the check inside the sending tool.
Example
- You enter
- Sending domains
getacme.exampleandtryacme.example, tool Instantly (hostinst, targetprox.itrackly.com). - You get
- For each domain,
inst.<domain>is looked up: these example domains don't exist, so both read Not set up, with the fix "Add a CNAME with host inst pointing to prox.itrackly.com". A live domain gets Ready, Points elsewhere, No CNAME visible, HTTPS problem or Domain blocklisted. - Limits
- Up to 10 domains a run; the lookups allow ten a minute.
What does each sending tool expect?
Instantly asks for host inst pointing to prox.itrackly.com, and says another host name won't verify. Smartlead uses emailtracking pointing to open.sleadtrack.com by default. lemlist shows the host and target in each account, commonly custom.lemlist.com. Apollo generates the CNAME in its own setup screen, so paste the target it shows.
The custom tracking domain generator writes these records for your DNS host; this checker confirms they are live.
Why check HTTPS and blocklists too?
Tracked links open on the tracking host, so a missing or wrong certificate breaks every click until the tool issues one, which usually happens after it verifies the CNAME. And because every tracked link carries your domain, a domain on a blocklist such as Spamhaus DBL or SURBL can get mail filtered on the link alone. The check uses the same lookups as the CNAME lookup and the domain blacklist check.
No CNAME visible, while the name still answers with an address, nearly always means a proxied record: on Cloudflare, set the tracking record to DNS only (the grey cloud). The custom tracking domain guide covers the rest.
Who uses this tool, and for what?
- Cold email agencies
- Check tracking on every new client domain in one pass before campaigns launch.
- Inbox resellers
- Confirm the tracking CNAME on a batch of pre-warmed domains before handing them over.
- Founders
- Find out why Instantly says the tracking domain isn't verified, and what to change.
What can’t this tool tell you?
- Up to 10 domains a run, because of the lookup rate limits.
- It checks DNS, HTTPS and domain blocklists; it can't see whether the sending tool has verified the domain in your account.
- lemlist and Apollo targets vary by account; a wrong target typed in gives a wrong verdict.
- DNS changes can take hours to show; a fresh record may read Not set up at first.
Common questions
- How many domains can I check at once?
- Up to 10 a run. The CNAME and blocklist lookups each allow ten a minute, so run the next batch after a minute.
- Why does it say No CNAME visible?
- The tracking host answers with an IP address but no CNAME. Either it was created as an A record, or a proxy (Cloudflare's orange cloud) hides the CNAME. Tracking tools usually can't verify it like that.
- Does it work for Apollo?
- Yes. Apollo shows a CNAME target per account in its setup screen; pick Apollo and paste that target with your subdomain.
- Which blocklists are checked?
- The domain blocklists the domain blacklist check queries, such as Spamhaus DBL and SURBL, for the sending domain's registered name.
- What is sent to your server?
- The tracking host names and the domains, for the DNS lookups, one HTTPS request to each tracking host and the blocklist queries. Nothing else.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
- Bulk verification with real SMTP mailbox checks
- Hard bounces removed before a send, not discovered after
- Catch-all, disposable and role detection on every row
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.