Auto accept agent is setup on a single mailbox. Since it is 2003, it is running as the local system. I have confirmed it is installed and operating as expected. I have gone over every AAA document known to man and can not find similar behavior. When a user adds a the mailbox to the list of attendees and selects send (or send update), the room is booked (or declined if it is already booked) but they never receive a notification. I opened up the mailbox and found an NDR/Undeliverable in the deleted items. Upon opening the NDR, I found the following: From: System Administrator on behalf of System Administrator To: Conference-Room-A Subject: Undeliverable: Accepted: ... Body: Your message did not reach some or all of the intended recipients. The following recipients could not be reached: Conference-Room-A on Any ideas? I put AAA on the highest logging settings and it does not glean any useful information. In message tracking, I found the recipient address is correct but an NDR is still generated.

have you seen below? Troubleshooting Auto Accept Agent http://technet.microsoft.com/en-us/library/bb124651%28EXCHG.65%29.aspx http://msexchangeteam.com/archive/2006/03/15/422141.aspxVinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

Yep. I assumed my original post made it clear I went over every AAA document known to man. Guess not. This isn't related to AAA. I was able to resolve the issue. It was because the Information Store hit its Named Properties Quota Limit (Event ID 9667). This took me forever to associate the two issues as I was assuming the issue was directly related to AAA. I discovered this by migrating a few test accounts between information stores. The information store that had hit the quota limit was the only one affected. The mailboxes in the other stores worked fine. What was interesting is even after following the instructions on technet (http://support.microsoft.com/default.aspx/kb/820379/en-us) and restarting all the Exchange services, I was still getting the error in the event log and the NDRs (even after a reboot too).