Running RC4.6, and I realize the current DNS editor has it's restrictions, and a new one is on it's way - but there's at least one glaring issue in it right now.
It wont allow me to create a subdomain with an underscore....
And that is preventing me from integrating with MailGun. MailGun requires TXT records to be added against a subdomain pic._domainkey of the domain that you want to use their service on.
So, unable to add the subdomain with the underscore means unable to interface with MailGun.
Now, before you start quoting articles on what is, and isnt permitted in the domain name, please remember
- this is a subdomain, not a domain name, so the RFC about the domain name doesnt apply
- DomainKeys always use the _domainkeys subdomain, and deeper nesting
- the DomainKeys project (http://domainkeys.sourceforge.net/) identifies that underscores are allowed under specific circumstances
However, what I think the biggest requirement for support for the underscore in the subdomain is this is already out there, in the wild, functional and fully in use by thousands of customers of MailGun (and Microsoft - go check the content of an AD domain hierarchy) and no doubt others - it needs to be supported on the subdomain.