How to view email count for folders such as Inbox, Sent Items, & custom Folders created in Outlook online?
The reason I say Outlook online is because another way to check for mail on Outlook is with the desktop application. Outlook as a desktop application seems very apparent that it's capable of showing email count after tinkering, but not for the Office 365 Online variant of Outlook for web mail by Microsoft.
UPDATE: user JRL has stated an answer to try.
Best Answer
That feature is not available on OWA. However, it is highly voted in uservoice:
Outlook on the web (Office 365)