Hey @kattm
Yes, you can absolutely use name@rootdomain.com as your visible From address in flows. You do not need to send from name@subdomain.rootdomain.com.
Here is why that works, and where the actual risk lives.
When you set up a branded sending domain in Klaviyo, you delegate a subdomain (something like mail.yourdomain.com or send.yourdomain.com) to Klaviyo. That subdomain is what handles the technical authentication layer: SPF, DKIM, and the return-path. It works silently in the background and recipients never see it. Delegating your subdomain gives Klaviyo authorization to manage DNS records for authentication purposes only, and it does not impact your root domain or any other subdomains. Klaviyo article on this here
Your From address (the one your team sees and recipients see) can stay as name@rootdomain.com. For DMARC compliance, the root domain on your account just needs to align with the from-address domain of your emails, so as long as both share the same root (they do, since mail.yourdomain.com and yourdomain.com share yourdomain.com), you are fine. Klaviyo article on this
Now, the reason Klaviyo and most deliverability guides push you toward a subdomain sending setup in the first place is reputation isolation, not the From address itself. If you were only using a root domain and got an increase in spam reports on a marketing campaign, the impact to your sender reputation would affect deliverability of all emails using the root domain, including sales outreach, customer support, or even employees emailing each other. The subdomain sending domain contains that blast radius to your marketing stream only. Klaviyo Community
So your idea to keep name@rootdomain.com as the From address for replies makes sense and will work. Just make sure your branded sending domain (the subdomain) is properly configured in your Klaviyo account settings, and set a Reply-To address if you want replies routed somewhere specific.
I hope this helps and thank you for posting your question here in the community.
Cheers
Arpit
