NSLOOKUP is a quick and convenient way to verify that your DK/DKIM records are set up properly. The policy for DK/DKIM is a TXT record at this location:
_adsp._domainkey.<domain.com>
For the selector record you have to use:
<selector>._domainkey.<domain.com>
For example, do a NSLOOKUP for TXT at: c3po._domainkey.altn.com
Open the Start menu Select Run... Type cmd [Enter] In the command window, type: NSLOOKUP [Enter] Type: set q=txt [Enter] Type: dcontrol._domainkey.tweenpath.net [Enter]