We are running Exchange 2007 SP1 with Rollup 10. Our environment has all the User Mailboxes on a single Exchange 2007 server that has all the server roles installed (less than 200 mailboxes total). We went from Rollup 6 to Rollup 10 because external meeting invitations generated by a delegate with Send On Behalf Of privileges were being dropped at the Hub Transport when sent to an Internal Mailbox that had a Delegate with Send On Behalf of rights along with being assigned to Receive All Meeting Requests without a copy being sent to the Mailbox that was invited. The setup goes Internal User A makes User B their Delegate via the Outlook 2007 Options, Delegates Tab. Delegate Permissions are set to the Default as Editor for Calendar and Tasks, and the check mark is placed for 'Delegate receives copies of meeting-related messages sent to me.' Further, on the Delegates tab, the option is set for 'Deliver meeting requests addressed to me and responses to meeting requests where I am the organizer to:' is activated for 'My delegates only.' The Delegate also has Send On Behalf Of permissions when it comes to Meeting-Related items. External User C creates a meeting request to Internal User A using an email program like Hotmail, Yahoo!, GMail - something that makes an appointment in the file.ics format. The Invitation is delivered to Internal User A instead of routing to the Delegate Internal User B, with the invitation being an attachment. It would seem that the Rule no longer recognizes .ICS based messages as being a Meeting-Related Message. Any feedback on how to correct this would be appreciated. Jim_At_Work

Two things have come to light. First, the original meeting request was a corrupted in transit or when sent. This was discoverd by going to http://severinghaus.org/projects and validating the file (link found in a different thread about ICS messages on the technet forums). The tip off was that the original meeting request was recieved as an attachment titled "not supported calendar message.ics". In subsequent testing, the meeting requests that did not route properly were attachments called invite.ics, which when opened, look like a meeting request and stated that the meeting request had been sent to a delegate which had not responded on behalf of the invitee. As it turns out, the external test mailbox was using Yahoo! email calendars - that service is in Beta testing. Those invitations did not route properly. A G-Mail generated invitation routed properly, did not arrrive as an attacment, and showed up only in the Delegate mailbox as requested, along with a Hotmail calendar invitation. Odd set of circumstances, but definitely not an Exchange 2007 issue.