Custom tracking domain generator: the CNAME for Instantly, Smartlead or lemlist
In short: Pick Instantly, Smartlead, lemlist or another tool and paste your sending domains. Get the CNAME host and target from the tool's own help article for each domain, formatted for your DNS host, plus the exact value to paste back into the tool. Limit: Values are from each tool's help article on 3 November 2026; if your account shows different ones, use those.
A custom tracking domain is a CNAME on a subdomain of your sending domain that points to your sending tool's tracking server. Instantly's guide asks for host inst pointing to prox.itrackly.com; Smartlead's uses emailtracking pointing to open.sleadtrack.com; lemlist shows the values in each account, commonly custom.lemlist.com. Paste your domains to get every record and the value to paste back.
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
Sample result
Smartlead's tracking domain for getacme.example is a CNAME: emailtracking to open.sleadtrack.com.
- Tool
- Smartlead
- Host
- emailtracking
- Target
- open.sleadtrack.com
What this means for you
Add it as DNS only, then paste http://emailtracking.getacme.example into Smartlead and verify.
- Host and target from each tool's guide
- One domain or 100
- Value to paste back into the tool
- Cloudflare DNS-only note
- CNAME
- Tracking
- Cold email
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
How do I set up a custom tracking domain for cold email?
- Paste your sending domains, one per line, and pick your sending tool. For a tool not listed, enter the CNAME target it shows you.
- Pick your DNS host so the host name and value are written the way its panel or zone file wants them, and change the host label if your tool lets you.
- Add the CNAME at your DNS host. On Cloudflare, set it to DNS only. lemlist also asks for a TXT record it generates, shown as a marked row.
- Paste the value shown under each domain back into the sending tool and run its check. Then look the CNAME up to confirm it resolves.
Example
- You enter
- The sending domain
getacme.example, with Smartlead as the sending tool and the standard DNS host format. - You get
- CNAME host
emailtracking, valueopen.sleadtrack.com, andhttp://emailtracking.getacme.exampleto paste into Smartlead's custom tracking domain field, with the DNS-only note for Cloudflare. - Limits
- Up to 100 domains a run; the records are built in your browser.
What is a custom tracking domain?
Open and click tracking works by rewriting the links in your email and adding a tracking image, both pointing at the sending tool's servers. By default those use the tool's shared domain, which many senders use at once. A custom tracking domain is a subdomain of your own, such as inst.getacme.com, that points at the same servers through a CNAME, so the links in your email carry your domain instead.
If you don't track opens or clicks, you don't need one. lemlist's guide says a custom tracking domain is required on its platform if any campaign tracks opens or clicks (lemlist).
Which CNAME does each sending tool use?
Instantly: host inst, target prox.itrackly.com, and the guide says to use inst exactly, because another name such as ins won't verify (Instantly). Smartlead: host emailtracking, target open.sleadtrack.com, entered back into Smartlead as http://emailtracking.yourdomain.com (Smartlead).
lemlist shows the host and target in each email address's settings, commonly custom.lemlist.com, and then generates a TXT record for the root of the domain to prove ownership (lemlist). The generator writes the common form and marks the TXT row; use the values lemlist shows if they differ.
Why won't my tracking domain verify?
Usually one of three things. The host is wrong (a typo, or the full domain typed into a panel that adds it again, giving inst.getacme.com.getacme.com). The record is proxied on Cloudflare: Instantly and lemlist both say to set it to DNS only, the grey cloud (Instantly). Or DNS hasn't updated yet: Instantly's guide allows 24 to 72 hours and Smartlead's 30 minutes to 24 hours.
The CNAME lookup shows what the subdomain resolves to right now. If it shows the tool's target, the DNS side is done and the tool only needs to run its check again.
What does each tool ask for?
| Tool | Host | Target | Paste back into the tool |
|---|---|---|---|
| Instantly | inst (exactly) | prox.itrackly.com | inst.yourdomain.com |
| Smartlead | emailtracking | open.sleadtrack.com | http://emailtracking.yourdomain.com |
| lemlist | As lemlist shows (e.g. trail) | As lemlist shows (commonly custom.lemlist.com), plus a TXT at @ | The tracking subdomain |
From each tool's help article, checked 3 November 2026.
Who uses this tool, and for what?
- Cold emailers
- Set up tracking on every new sending domain with the exact host each tool insists on.
- Agencies
- Give a client's IT team one CSV with the tracking CNAME for each of their domains.
- Teams switching tools
- Rewrite tracking records when moving from one sending tool to another, for every domain at once.
- RevOps
- Keep a record of which tool each tracking subdomain points to.
What can’t this tool tell you?
- Values are from each tool's help article on 3 November 2026; if your account shows different ones, use those.
- lemlist's TXT value is generated per tracking domain; the tool marks it and says where to get it.
- It writes records; it doesn't check them. The CNAME lookup and the cold email domain checker do.
- It covers the tracking CNAME only; MX, SPF, DKIM and DMARC are in the bulk DNS records generator.
Common questions
- Does a custom tracking domain improve deliverability?
- It moves your tracked links off a domain shared with other senders onto your own, so another sender's reputation on that shared domain isn't attached to your links. It doesn't fix authentication, content or a bad list.
- Can I put the CNAME on the root of my domain?
- No. A CNAME can't share a name with the domain's other records, so it goes on a subdomain such as inst or emailtracking. The tool won't let you use @.
- One tracking domain for every sending domain, or one each?
- Smartlead's guide allows either: one tracking domain for every mailbox in the account, or one per sending domain. One per sending domain keeps each domain's links on that domain, so a problem with one doesn't touch the others.
- Why does Cloudflare break it?
- A proxied record answers with Cloudflare's own addresses instead of the CNAME, so the sending tool can't see that it points to its server. Set the record to DNS only.
- How long does it take to work?
- Instantly's guide allows 24 to 72 hours and Smartlead's 30 minutes to 24 hours. It is often quicker; the CNAME lookup shows when it is live.
- Does it work for tools that aren't listed?
- Yes. Pick Another tool, enter the host and the CNAME target your tool shows, and the generator formats the record for every domain.
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.