Here is my Problem:User got deleted two or three months ago (left the organization). No more exists in the Active directory but he was part of a DL at that time...Now when other users send messages to this DL, they get undeliverable error message for this deleted user with error code #5.1.1.I checked the DL membership, the user is not there.I verified whether the sender was using any personal distribution list and she is not.Can you tell me what could be the issue?Thanks,Raj

Hi,You should have a look with the mfcmapi tool, I once had the same issue with a resource calender. With the tool you can edit the database directly so be carefull doing this.Regards,Johanblog: www.johanveldhuis.nl

Yes I agree with Johan, if senders are getting NDRs when they send meeting invitation or responses, this must be some stale delegates rule configured into recipient's mailbox.Check similar thread for the detailed steps to be performed on recipient's mailbox.http://social.technet.microsoft.com/forums/en-US/exchangesvrgeneral/thread/8ef3fa80-7692-4402-b788-39774a2e81e9/Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com