Exchange Server 2010 SP1 Beta Now Available for Download

Under most circumstances, deletions with Outlook 2003 do seem to be faster against an Exchange 2010 SP1 Beta CAS than an RTM CAS; they take about three seconds, even without reducing the Maximum Polling Frequency a la KB2009942.  I've also noticed that when deleting messages from the folder view, you get the hourglass right away until the message disappears three seconds later, so you can't hit the delete key twice on the same message and trigger the "Unknown Error" by double-deleting the same message. Unfortunately, you can't do anything else during those three seconds, either.  The display also seems to update when single clicking on any other message in the same folder, which is also an improvement (with RTM, you'd have to click into a different folder, then click back to the original folder).  However, you can still trigger the double-deletion "Unknown Error" under at least one specific circumstance: if you open a previously read message by double-clicking it and delete the message by clicking on the delete button in the message window, when the message window disappears, the message is still listed and highlighted in the inbox folder view.  If you click anywhere else in the inbox, the message disappears instantly, but if you hit the delete key while the message is still highlighted, you get the dreaded "Unknown error" pop-up.  This doesn't happen if the message you open is unread; in that case, following the same procedure, the message disappears from the inbox immediately.

Microsoft clearly did something to change the way Outlook 2003 interoperates with a CAS, but I just don't understand why they didn't simply restore the UDP notifications and be done with it.  Three seconds to delete a message in the folder view is still an eternity for most users, especially when deleted messages disappeared from the inbox instantly the previous day, before their mailbox was migrated from the Exchange 2003 server to the Exchange 2010 server.  If Outlook 2003 is supported, then Microsoft shuld fully support it, not just "kinda" support it.  Removing UDP notifications has completely screwed us up here.