How to re-enable check boxes to select multiple emails for bulk actions?

Click the Select icon—the small box at the right of the current folder’s name—to enter selection mode and restore the checkboxes beside messages.

1. Open Inbox or the folder containing the messages.
2. At the top of the message-list pane, find the folder name.
3. Click the Select box on its right.
4. Check the messages, then choose Move, Delete, or another bulk action from the toolbar. This is the reported current workflow in both Outlook on the web and new Outlook for Windows.^1^ A matching Outlook Q&A resolution identifies the same Select control beside the folder name.^2^

There is currently no documented setting that restores the checkboxes as a permanently visible column. Microsoft’s available message-list settings under Settings → Mail → Layout cover organization, reading-pane appearance, Focused Inbox, and sender/subject formatting, but not persistent selection checkboxes.^3^

If the Select icon itself is absent in both clients, this is no longer just the expected hidden-checkbox workflow. In Outlook on the web, use Help to report the issue; for a business account, also ask the Microsoft 365 administrator to check whether other users are affected and open a Microsoft 365 support request if it is organization-wide.

References

1. Message List Selection UI updates for Outlook on the Web and New ...
2. Check boxes have disappeared - Microsoft Q&A
3. Change how the message list is displayed in Outlook