Is it legit? "Authenticate and add a DMARC record to continue sending emails from your domain"

Thanks Imogen. I have 5 logged support chats with Shopify since end of January when the DMARC notification came through and I transferred my domain (which I’ve had, relatively problem-free for several years). One of the support chats, the advisor failed to log the chat! The last logged chat, the advisor asked me to re-verify with my email provider (Zoho) which I’ve done. Domain is authenticated, DNS settings are okay. DMARC checks out as okay. But still the outgoing email from @t.shopifyemail.com. I’m hesitant to waste more time logging into advisor, since they don’t seem to know what the problem is on Shopify’s end. I’m suspicious it’s not just me, because I’ve noticed another vendor who uses shopify suddenly sending emails with @t.shopifyemail.com instead of their domain as well when I made a purchase. Any help, suggestions appreciated because the advisors are struggling to provide meaningful and timely help, and no follow-up as in the past. Thanks