Question: Can I access Exchange Server 2010 Public Folders using an IMAP email client?
In Exchange Server 2003 it is possible to connect to public folders using an IMAP4 connection. However in Exchange Server 2010 this feature is no longer available.
Microsoft’s advice on the Discontinued Features list for Exchange 2010 is:
If you need this functionality, retain an Exchange 2003 server in your Exchange 2010 organization.
Keep in mind that Exchange organization that is migrating to Exchange 2010 can stay in a co-existence state with Exchange 2003 indefinitely, so this is not an impractical solution. However you do need to be aware of the end of life date for Exchange Server 2003 and plan to move away from it at some point.