Microsoft has released rollup 3 for Exchange Server 2007. You can download it here. This rollup also contains all the fixes from rollups 1 and 2. It is also rumored to also contain a fix that allows for IMAP connectivity to the soon forthcoming Apple iPhone. Other fixes include:
• 931328 (http://support.microsoft.com/kb/931328/) An integer is added to the end of the legacyExchangeDN attribute of a newly created mailbox in Exchange 2007
• 930468 (http://support.microsoft.com/kb/930468/) The attachment is not displayed when you use Outlook 2003 to open an e-mail message that contains an attachment
• 931842 (http://support.microsoft.com/kb/931842/) Error message when the sender or the receiver of a meeting request has a double-byte character set (DBCS) display name in Exchange Server 2007: "The requested property was not found"
• 932207 (http://support.microsoft.com/kb/932207/) Error message when a user tries to open a forwarded message to accept or to deny a resource request in Exchange Server 2007: "Cannot open the free/busy information"
• 932515 (http://support.microsoft.com/kb/932515/) You receive a 5.2.0 non-delivery report (NDR) message when you send an e-mail message to an Exchange 2007 server that is running the Isinteg.exe tool in a dismounted mailbox store
• 934887 (http://support.microsoft.com/kb/934887/) DBCS characters are converted into two question marks in a forwarded e-mail message in Exchange 2007