Jimmy KimCEO & Founder, Commerce Roundtable · Marketer of 17+ Years, 4x Founder. Former DTC/Retailer & SaaS Founder. Newsletter. Host of ASOM & Send it! Podcast. DTC Event: Commerce Roundtable

How to Set Up Email Subdomain for ESP Migration (Step-by-Step)

2 Apr 2026 · 1 min

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1:01

In this interview segment, Jimmy Kim explains how to set up a dedicated sending subdomain for email marketing migrations. He advises users to log into their domain registrar—such as Shopify, GoDaddy, Namecheap, or Cloudflare—and create a free subdomain (e.g., email.yourbrand.com, mail.yourbrand.com, send.yourbrand.com). He then describes how modern ESPs like Omnisend provide guided wizards that walk users through configuring the new sending domain. The wizard prompts the user to add three essential email authentication records: SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance). The conversation ends with a request for clarification on what each of these records actually does.

How do you recommend someone setting up this subdomain?
So you go to your domain provider, it could be Shopify, GoDaddy, Namecheap, Cloudflare, whatever you use, and you create a subdomain, which is absolutely free. Things like email.yourbrand or mail.yourbrand or send.yourbrand. I mean, you can kind of use whatever you want.
Okay, and then from there, what do you do?
Well, the good news is the fancy ESPs now have great little setups that make this pretty easy. So if you're in an Omnisend, for example, they have a step-by-step guide. For configuring your new sending domain.
That's also too where you're going to set up your authentication, correct?
Right. So they're also going to tell you to do those 3 things that come with it. And it really depends on how the wizard's set up and how you go through it. But there's the SPF, which is the whole Sender Profile Framework. You've got the DKIM, which is like the DomainKeys Identify Mail, and then your DMARC, which is your Domain-Based Message Authentication.
You know, I think we've all heard these words. We all know that we need to do them, but what do they actually do?
All they do is they prove to Gmail, Yahoo, or whatever inbox provider you're emailing to that you're authorized to send emails from this domain.