Hi, I have an Exchange 2007 envvironment comprising of 2 HUB/CAS and 2 Mailbox servers in SCC cofiguration. Initially i upgraded the HUB/CAS from Exchange 2007 SP1 to Exchange 2007 SP2. Everything continued to work flawlessly. But ever since i applied the SP2 to the Mailbox servers I started experiencing the following: 1. Outlook 2007 users started experiencing problem updating their folders. for eg. when i send a message it gets stuck at "Sending". However, it does go through actually and is received by the recipient(s)--both internal and external. But in the Outlook it stays in the Outbox in the "Sending" state (same applies to receiving through Outlook, meaning it doesn't update the inbox, just keeps processing). In OWA it can be found in the Sent items folder, though. Outlook is in Cached mode btw (like before the SP2 update). Bottomline: OWA continues to update folders successfully, Outlook doesn't. 2. In OWA, users experience mailbox connectivity issues intermittently. For eg, a user is connected for a while but after some time unable to work. The session is timed out and they receive the message that there was trouble accessing their mailbox and they should sign in again. But even after signing back in, it happens again. Could someone please shed some light as to why this might be happening? Is this a known SP issue or something that's to be expected after applying the update? I'm not receiving any warning/error events on either the Exchange server or the client machines and everything appears to be "normal" from the server point of view As I mentioned everything was working perfectly on Exchange 2007 SP1 and even after upgrading the HUB/CAS servers to Exchange 2007 SP2. Please note this is happening to multiple users (may be all of them--just received confirmation from some) and in my opinion it's definitely a server issue. Still I have recreated the profiles, tested same user on different machines and all that. Please don't suggest to upgrade to SP3 (as i mentioned everything was going smoothly and this happened ONLY AFTER i updated the Mailbox servers to SP2) as i dont want to make the issues more complex/possibly create new ones, unless of course it's a known bug in SP2 and it's confirmed to be fixed in SP3. Temp Solution: I restart the Information Store and Outlook starts updating the folders again but after some time (a few hours) it's back to the problematic state. Thanks and sorry for multiple posts.. Regards