In the High Assurance Domain (HAD) Monitor, entries marked with "DKIM?" in the DKIM field are zones where the monitor cannot determine if the zone uses DKIM to authenticate sending MTA's. DKIM requires the knowledge of a unique string (called the selector) in order for a client to query for the correct public key.
If you are the administrator or user of a zone that you know uses DKIM, let us know by sending an email from your zone's MTA, we can extract the needed information and add it to the monitor input file. Please set the Subject line to "DKIM-submission" and feel free to leave the body of the message blank. It is not needed and will not be read. The DKIM key will be monitored from that point onward.
Once the HAD-monitor has the data, it will query for the DKIM key during each monitor scan and no more action is required on the administrator's part. However if the DKIM key changes, we would like to know the new key. It can be submitted using the same process.
A more complete set of tests for DKIM (and other trustworthy email techniques), please go to the HAD Email Authentication Test Tool. Sending and email to the test system can also register your domain's DKIM key for future reference.