How to share a folder with another user in M365 Outlook (Windows)

Folder sharing: To grant access to Inbox, subfolders and custom top-level folders without Sharing invitation:

1.Highlight the folder you want to share > right-click this folder > choose Properties.

Highlight the folder you want to share > right-click this folder > choose Properties

2. In the Properties window switch to the Permissions tab > click Add. Check the name of the folder you are going to update (top left corner has the folder name).

3. Type a name in the search field, the click to select the name, then click Add. Repeat this as needed, then click OK

4. In Permissions, highlight user > set permissions (choose the level of permissions from the menu or set manually) [permission level details below]
In Permissions, highlight user > set permissions (choose the level of permissions from the menu or set manually) [permission level details below]

Owner: Allows full rights to the mailbox, including assigning permissions; you should not assign this role to anyone.

Publishing Editor: Create, read, edit, and delete all items; create subfolders.

Editor: Create, read, edit, and delete all items.

Publishing Author: Create and read items; create subfolders; edit and delete items they've created.

Author: Create and read items; edit and delete items they've created.

Nonediting Author: Create and read items; delete items they've created.

Reviewer: Read items.

Contributor: Create items.

None: Gives no permissions for the selected accounts on the specified folder.

5. Click Apply and OK to complete granting permission

Click Apply and OK to complete granting permission