You can share any of your mail folders, including the Inbox folder and sub-folders. You select the folder(s) and specify the type of access permissions to give the Grantee. You can share with internal users who can be given complete manager access to the folder, external guests that must use a password to view the folder content, and public access so that anyone who has the URL can view the content of the folder.
When internal users share a mail folder, a copy of the shared folder is put in the Grantee's Folder list on the Overview pane. When the folder is selected, the content displays in the Content pane. You do not need to log on to the Grantor's mailbox.
Your sales department wants one central mailbox for all email messages requesting information about your product, and everyone in sales should be able to view email messages immediately when they come in. You can give everyone in the department permission to view the mail folder and they can copy the messages to their mailbox, or you can give them permission to manage the mail folder and they can reply on behalf of this address.
A manager is often out of the office and does not have time to respond to her email messages. When the manager delegates access to her Inbox mail folder, her assistant (grantee) can manage the content of her mail, respond to messages on her behalf, create folders to organize message in that mail folder, and delete messages.
Instead of sending email messages to dozens of addresses every time you have an announcement, you can identify one of your folders as a public folder that contains the email announcements. You can create shared access to only specific email addresses and set a password that must be entered to view the content, or you can make it a public URL for anyone who has the URL can view the content.