Changing root domains when adding a sending domain returns root_domain_mismatch

Hi ​@Hutch ,

Thank you for reaching out! I can confirm that root_domain_mismatch is expected here. Klaviyo’s gradual Active-to-Warming transition supports moving between subdomains under the same root, such as send.crunchypupco.com to mail.crunchypupco.com. It does not support running send.crunchypupco.com and send.mycrunchypup.com as parallel Marketing sending domains in the same account.

For a different root domain, use a sequential replacement:

1. Choose a low-volume maintenance window and avoid scheduled campaigns.

2. Put the live welcome-flow messages into Manual mode before the change. This holds recipients in Needs Review so they do not send automatically. If you do not want new recipients queued at all, use Draft instead. Do not archive or delete the flow, because that cancels queued recipients.

3. Keep the existing crunchypupco.com DNS records in place temporarily for rollback, but remove or deactivate the old branded sending-domain configuration in Klaviyo so the new root can be added.

4. Add send.mycrunchypup.com as the new Marketing branded sending domain and publish the Klaviyo-generated DNS records. The Google Workspace SPF, DKIM, and DMARC checks do not replace Klaviyo’s branded-domain setup.

5. Verify the new domain and activate it. Avoid sending while there is no active Klaviyo branded domain, since messages could use a shared Klaviyo sending domain during that gap.

6. Change the account default sender to the new @mycrunchypup.com address, then review the existing flow messages. Changing the default sender does not automatically update pre-existing flows and campaigns, although Klaviyo provides a bulk-update option.

7. Test the welcome flow with a small internal group, then release the held messages deliberately and return the flow messages to Live.

For messages already queued, Manual mode is usually the safer option if you want to preserve them. Recipients move to Needs Review and must be reviewed or sent manually. Messages in Waiting use the current version of the flow message when they send, so update the sender details before releasing them. Avoid setting a message to Draft if you need those queued recipients to receive it, because Draft messages are skipped.

Treat mycrunchypup.com as a new sending identity for deliverability purposes. The old domain’s Klaviyo sending reputation should not be assumed to transfer simply because the account and subscriber data are staying the same. Follow Klaviyo’s warming guidance for the new root, beginning with your most engaged recipients and increasing volume gradually. If the new domain has no established bulk-email history, the standard ramp is generally measured over the first 2–4 weeks.

Klaviyo’s branded sending-domain guide, domain-warming guide, sender-address guide, and flow queue guidance cover these steps. I would not remove the existing domain or change the live flow until the cutover window and rollback plan are ready.

I hope this helps! 

 

Temi@Klaviyo