The Office 365 portal often had a wealth of information regarding the status and health of your services.
One of the components that reports health through the portal is the status of DNS records for domains that are added to Office 365. You can observe this health reporting by accessing Setup –> Domains.
Your domains will be listed and domains that are currently flagged for issues display a warning symbol and are flagged for possible service issues.
To review the individual issues identified the domain can selected in the previous screen. The next screen displays the individual DNS associated with the domain selected.
With the DNS records displayed we can select DNS Errors detected, click here to view.
With this option selected we will see the individual DNS errors that were detected for the domain selected. Here is a sample for the MX records.
In this example our health logic has queried DNS and determined that the MX record provisioned for your domain is not the MX record found in the DNS registrations.
There are situations where this is perfectly acceptable. The DNS health checking mechanism does not know the specifics of your installation and any customizations that may be present. For example, it is not uncommon in a hybrid configuration to have your autodiscover record pointing to an on premises Exchange environment. This would trigger a health check failure on the CNAME records as autodiscover does not point to the Office 365 service. It is also not uncommon to have inbound mail flow for your MX record point to a solution other than Office 365 – for example a third party gateway device <or> an on premises email environment. This would produce a DNS health check failure on the MX record similar to the errors seen above.
When the health check has found an error it is important that the records be manually reviewed and an understanding of any discrepancies explained. If they are due to customizations the errors can be safely ignored. If they are due to legitimate DNS errors it would be recommended to fix the discrepancies as soon as possible to prevent any forms of service outage.
If you analysis has determined that the DNS errors are benign you can discontinue warning about them by selecting the ignore incorrect dns button. This is found on the same page where the individual DNS record errors are displayed.
If the administrator has selected the ignore incorrect dns option the domain will no longer appear with a warning symbol on the domains page and the status will show setup complete verses possible service issues.
If at a later time you decide you want to have DNS re-evaluated for any reason you can select the specific domain and utilize the CHECK DNS button to initiate a DNS health check.
With an understanding of your DNS implementation and a review of the service issues identified administrators and make an accurate determination if the errors are safe to ignore or if actionable steps need to be taken.