Tumblr custom subdomain stoped working

Question

I have added my custom .tk subdomain to Tumblr. My DNS setup for this domain looks like this:

A   - mydomain.tk  -   xx.xxx.xxx.xxx ;   
MX  - mydomain.tk  -   xxxxxx.pamx1.hotmail.com ;        
CNAME - blog.mydomain.tk - domains.tumblr.com

It was working fine for a month or more, and then all of the sudden I get this error:

This subdomain's CNAME is not pointing to Tumblr. It is currently set to “DOMAINS.TUMBLR.COM”.

Obviously my domain is set correctly. This error doesn't make sense that the domain is not pointing to DOMAINS.TUMBLR.COM when it is pointing to DOMAINS.TUMBLR.COM.

When I open my adress blog.mydomain.tk, it opens the Tumblr site and shows an error: "There's nothing here." So obviously the problem has to be on their side, right? I wrote to their support about this and first time they fixed it immediately, and then after a couple of hours it happened again, without me even doing anything and now even their support doesn't answer me.

Answer 1

The CNAME looks correct according to Tumblr's support doc on using a custom domain name, and if you're reaching a page on their end (as seen before), it's resolving to their servers.

The problem might be related to the .tk ccLTD: Since its registrations are offered free of charge, spam and phishing operators have historically abused .tk domains - see this and this for more on that. So it might be triggering Tumblr's filters.

There are also significant restrictions placed on using .tk domains by the registry, as stated here:

There are content restrictions for free domains, banning sites containing sexual content, drug use, hate speech, firearms, and spam or copyright infringement. Also if a domain's redirect target does not work (even temporarily) the domain is taken offline. If a domain violates any of these terms, it is replaced by a Sedo ad page, and no beforehand warning is given. Expired pages (except for those that received complaints of content violations) can be reclaimed by contacting their support system.

Noting the second sentence above, the registry could also take the domain offline if a redirect doesn't work "even temporarily".

So although the problem may lie on Tumblr's end, you might consider obtaining a generic top level domain (gTLD), which are not very expensive at some registrars. They would have fewer restrictions with more widely accepted recognition.