I'm running into the same problem as many other folks I've seen on the developer.apple.com. However, none of them have solutions yet.
I run a small ISP and we have our DNS on OpenSRS Managed DNS.
2 Questions: Do these DNS entries look correct? I've quadruple checked them and I still get the "Check your txt record" error. Plus, all e-mail destined for this domain now bounce.
Are there examples of existing domains out there that are working that we can reference in a 'dig', nslookup or similar for comparison?
cappelli@M2 ~ % host -t TXT dslwest.com
dslwest.com descriptive text "v=spf1 include:icloud.com ~all"
dslwest.com descriptive text "apple-domain=hudfp9wtd2pjzy5k"
cappelli@M2 ~ % host -t MX dslwest.com
dslwest.com mail is handled by 10 mx01.mail.icloud.com.
dslwest.com mail is handled by 10 mx02.mail.icloud.com.
cappelli@M2 ~ % host -t CNAME sig1._domainkey.dslwest.com
sig1._domainkey.dslwest.com is an alias for sig1.dkim.dslwest.com.at.icloudmailadmin.com.
Thank you.