Cold Email Setup · 5 min read

Instantly Setup: Custom Tracking Domain, SPF, DKIM, DMARC

Instantly sends cold email through the Google Workspace, Microsoft 365 or SMTP mailboxes you connect. That means your SPF, DKIM and DMARC come from the mailbox provider, and Instantly adds one record of its own: the custom tracking domain. Here is the full setup for each sending domain.

Published October 26, 2026

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What Instantly handles, and what you must set up

Instantly does not send mail from its own servers for your domain. It logs in to the mailboxes you connect and sends through them. So the provider of those mailboxes is the one that must be in your SPF record and must sign with DKIM. Instantly's only DNS record is the custom tracking domain, which puts open and click tracking links on your own domain instead of a host shared by many senders.

Step 1: SPF, DKIM and DMARC on every sending domain

Do this on each secondary domain you send from, not only the main one.

RecordGoogle WorkspaceMicrosoft 365
MXsmtp.google.com (priority 1)The host shown in the Microsoft 365 admin center (often *.mail.protection.outlook.com)
SPF (TXT at @)v=spf1 include:_spf.google.com ~allv=spf1 include:spf.protection.outlook.com ~all
DKIMTXT at google._domainkey, generated in Admin console → Gmail → Authenticate emailCNAMEs at selector1._domainkey and selector2._domainkey, then turn DKIM on in Microsoft Defender
DMARC (TXT at _dmarc)v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

Keep one SPF record per domain. If the domain also sends through another service, add its include to the same record and stay under 10 DNS lookups.

Step 2: The Instantly custom tracking domain

Type:   CNAME
Host:   inst            (becomes inst.yourdomain.com)
Value:  prox.itrackly.com

Then in Instantly: In the settings of each email account, find Custom tracking domain. Enter inst.yourdomain.com and click Check Status; save only after both the CNAME and SSL show as verified.

Source: Instantly help center. Check it if the value changes; tracking providers sometimes move hosts.

Do you need open tracking at all?

Open tracking adds an image to every email, and Apple Mail Privacy Protection loads those images automatically, so open rates are no longer reliable. Many cold email teams turn open tracking off and measure replies. If you track clicks or opens, use a custom tracking domain so your links do not share a reputation with every other Instantly customer.

Instantly-specific notes

  • Older Instantly guides use the host "track". Instantly now recommends "inst" instead; both work if the CNAME points to prox.itrackly.com.
  • Instantly says CNAME changes can take 24–72 hours to show. Check the record with a CNAME lookup before you click Check Status again.
  • Done-for-you and pre-warmed domains bought through Instantly get the tracking CNAME set up automatically. Still check SPF, DKIM and DMARC on them.
  • On Cloudflare, a proxied (orange cloud) CNAME usually breaks tracking hosts; set it to "DNS only".

Step 3: Check every domain, and keep checking

Run the cold email domain health check on up to 5 sending domains at once. Most problems appear later, not on day one: a DNS move drops the DKIM record, someone adds a second SPF record, or a domain lands on a blocklist. Domain monitoring checks every domain daily and sends one alert with the fix.

Know the day your email setup breaks

Most delivery problems start when a DNS record changes, a key is removed or a domain lands on a blocklist. EmailHealth checks your sending domains every day and sends one alert, by email, Slack or webhook, with the exact fix.

1 domain free. Sending from many domains (cold email, agencies, MSPs)? Early access covers 10.

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Check up to 5 sending domains