Hello, A public folder is just a folder added for users to be able to view it in their Outlook and use according to permissions. However I recently read about Public folder access with NNTP, IMAP4, non MAPI How does these relate to Public Folders ?

Hi, In exchange 2003, you can also view the public folder through NNTP and IMAP4 other than MAPI. Since exchange 2007, Public Folder does not support NNTP and IMAP4, we are only able to access public folder by MAPI protocal.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT

Hi, In exchange 2003, you can also view the public folder through NNTP and IMAP4 other than MAPI. Since exchange 2007, Public Folder does not support NNTP and IMAP4, we are only able to access public folder by MAPI protocol. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT