No New Folder Creation?

Folder creation is supported in Outlook for Mac, so every New Folder command being disabled is not expected behavior. Make sure you are in Mail and right-click the mailbox address or a mail folder, not Favorites, a search folder, Calendar, or a shared folder where you lack create permission. Then try creating the folder in Outlook on the web or webmail. If that also fails, mailbox permissions are the blocker. If web creation succeeds, update Outlook, restart the Mac, and switch from Legacy Outlook to the current Outlook; legacy support ends in October 2026. Let the new folder synchronize back. If one account is affected, remove and re-add that account after confirming all data is server-based. If the option stays disabled, use Help > Contact Support and include the account type and whether top-level and nested folders fail; reinstalling should not be the first step.