Every row says why the account is listed in one sentence, for example: "example.com points to 104.21.3.7, not this server; mail goes to Google (aspmx.l.google.com). None of its 3 other domains point here either."
Click Details to see every domain the scanner checked, what its website and mail records pointed to, and when.
Fixed the DNS? Click Re-check now in Details. If the account is active it leaves the list straight away. Each account can be re-checked once per minute.