This component takes you to the same place as Setup | Domains on the left-side navigation pane. The direct link options are Add a domain, Delete a domain, Edit a domain, and Check health, which checks on the DNS status of the domains you own.
It's a good idea, if you're not frequently looking at the advanced DNS options in your domain name provider, to occasionally check your DNS health. We've seen DNS entries that were placed when a domain was first migrated disappear from the clients' domain name provider, on occasion. This is particularly likely if your company has just migrated to a new provider or brought on a new website host, or has undergone other circumstances that could lead to changes to your domain. Office 365 is pretty ...
