Recently upgraded to openSUSE Leap 15.5 (with all updates applied) and came across a problem using YaST DNS Server Configuration tool. With Google on the verge of requiring SPF, DKIM, DMARC DNS changes, lest your outgoing mail not being delivered, I suspect this should be addressed quickly.
I am attempting to add a CNAME record with the following information:
A valid domain name consists of components separated by dots.
Each component contains letters, digits, and hyphens. A hyphen may not
start or end a component and the last component may not begin with a digit.
Through testing, I’ve found that is is complaining about the underscore character, ‘_’, that the domain key requires.
I have previous entries using the underscore character, “_”, submitted within previous versions of openSUSE/YaST, so I have to assume that is is a recent bug.
A DKIM record is really a DNS TXT (“text”) record. TXT records can be used to store any text that a domain administrator wants to associate with their domain. DKIM is one of many uses for this type of DNS record. (In some cases, domains have stored their DKIM records as CNAME records that point to the key instead; however, the official RFC requires these records to be TXT.)
So maybe they tightened the checks, not allowing the _ at the start anymore in CNAME records, but only in TXT records.
The problem is that Microsoft, Amazon SES, SendGrid, Constant Contact, HappyFox, etc require folks to enter CNAME records containing the underscore character, “_”, within your DNS. This isn’t currently possible within the YaST DNS Server Configuration tool.
With the tidal wave of Google SPF, DKIM, DMARC DNS changes that must be made before April 1 to ensure that your mail is delivered, this is a major issue.
For example, if you use Microsoft Office/Microsoft 365, you will have to make the following change to your DNS which are currently impossible from within the YaST DNS Server Configuration tool.