MailChimp now require you to add DKIM and SPF records to domains you own.
Unfortunately when you’re using CloudFlare CNAME flattening the DKIM verification fails since MailChimp’s servers are looking for their CNAME record, and CloudFlare’s nameservers are returning the actual TXT record.
To work around this:
- Temporarily disable CNAME flattening in CloudFlare settings (click the orange icon next to the DNS record so it got grey)
- Verify the domain in MailChimp
- Re-enable CNAME flattening
The verification should still stick.