i have been in converstation with my ISP about adding the cm._domainkey.ourdomain.com to our DNS. Not surprisingly they balked at the underscore. well i pushed them on this quoting both your help page and the sourceforge link which further links through to the RFC2782 about DNS RRs.
However their response is that they will not add it because it is not in an ISO standard. Now my question is, is this correct? Or if not, where is the ISO that explicitly allows it?
And I guess this leads to the question, if it is not in an ISO (and just the very fact you have a help page on this issue seems to demonstrate a lot of issues here) will there be an alternative approach which more ISPs will accept?
Hi, the domain key specification requires the underscore - it's not something we at Campaign Monitor have added in, so there really is no other way for us to work around it and still offer domain key authentication.
All the major DNS providers, like DNSMadeEasy for example can handle it without any problem, so your best option is to move just your DNS hosting to a more useful service who can provide what you need.
Some hosts just don't have the capability to do so, or for whatever reason don't want to allow it.
From what I can see, many hosts don't support the underscore. Seems like much work is needed on this.
It's true that many hosts don't handle it, but that is an issue with the hosts needing to get up to date, or their software platforms being updated.
I imagine we will see this start to happen more when major email providers start blocking email that is not authenticated.
Like Mat said in his first comment... DomainKeys are not something we (Freshview, Campaign Monitor) made, and therefore can't fix. Trust me, we wish we could!
You can read all about it on Wikipedia: http://en.wikipedia.org/wiki/DomainKeys
Mat is right though, the standard was only adopted as of last year and as is the case with all new technology, it can take a couple of years before you see wide adoption.
Hope that helps,