Hi,

I have DKIM set up system-wide.  Some domains are signed correctly and others are not.  Let me explain:

I have two domains - domain that is the also the "root" or domain name of the server and then I have a number of add-on domains. 

When I use mxtoolbox to check deliverability on the root domain (lets call it rootdomain.com), everything checks out as follows:

Ok - DMARC Compliant
Ok - SPF Alignment
Ok - SPF Authenticated
Ok - DKIM Alignment
Problem - DKIM Authenticated

In other words, everything checks out except the DKIM authentication.

No to make things more confusing, I have another domain (an add-on domain - let's call it addondomain.com) where everything works:
Ok - DMARC Compliant
Ok - SPF Alignment
Ok - SPF Authenticated
Ok - DKIM Alignment
Ok - DKIM Authenticated

DKIM key is the same for all the domains on the server.  

I triple checked and the settings for DKIM are identical for both domains in DNS.   DNS is hosted by company A for rootdomain.com and company B for addondomain.com.   DKIM file is identical on both.  Because emails sent from rootdomain are getting DKIM recognition on "alignment" I'm thinking the issue is with surgemail or my server rather than the DNS. 

However, I've tested with dmarcian.com and I get a similar result: emails sent from addondomain.com verifies just fine and rootdomain.com shows NO SIGNING for DKIM.

Again, it's the same key for all domains on the server.

Is the problem with authentication more likely to be a problem with the server or with the DNS service? 

Has anyone run into this before and what solution did you find to fix this?

Thanks for any input you might have!

Patrick