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.
4 Answers
Go to the gear at the top right of webmail for Outlook 365 (outlook.office.com) and select "View all Outlook settings" at the bottom. Then go to "General" and then "Storage." It will then show the size and count of messages for each email folder.
I haven't found where you can see the total count of Contacts or Calendar items.
That feature is not available on OWA. However, it is highly voted in uservoice:
Outlook on the web (Office 365)
2An altnertive is to right click the folder, and select Mark all as read. That will throw a confirmation prompt like below. You will have the count in that confirmation prompt.
In case the option is greyed out, you can use CTRL+A ( ⌘+A on macOS) to select all items on the folder, and try Mark all as read/unread
In Office 365, if you want to see all the emails of specific folder, just make everything as "Mark all as read" and then "Empty folder". When you click on Empty the folder, it will prompt "Do you want to delete n emails in this folder?"
This way, you will be able to tell the number of emails in the folder. However, this won't work if you have more than 10,000. It will say 10000+.
