Of my six databases, one does not place the Inbox at the top of the list of groups. Instead, it is located in its alphabetical location (e.g., between “Home Sale” and “iOS.” The other five databases all have their Inbox at the top of the list of groups. How do I repair this, please?
The sort order on the 6th database appears to be set to alpha. If you change it back to Unsorted (the default), it should again sort like your other databases. You can access the sort menu by rich-clicking in the list of groups.
That solved it. Thank you.
Glad you fixed it, because not everyone knows how to ‘rich-click’! 
Rich click? I don’t get it.
My typo in my first post.
