I have a customer using Outlook 2003 who sent a message to another client on my 2003 Exchange site with a read receipt on the message. After the message was read, the sender now receives another copy of that read receipt every minute...on the minute. I fixed the problem by detaching the senders mailbox from the store in Active Directory and then re-attaching it.
Does anyone have any idea what could have caused this, or has anyone seen this before?