Is it possible for Outlook to send a Read Receipt more than once? I have a user who has received a Read Receipt a couple of days ago for a message they sent about 10 months ago. The message tracking logs confirm that they received a Read Receipt initially just after they sent the message but then a second one was generated and delivered to them a couple of days ago. The Read Receipt is coming from a shared-access "generic" mailbox that can be accessed by more than one user.
Both mailboxes are using Outlook 2003 and hosted on a Microsoft Exchange 2003 mail server.
Yes, it is possible. Each message can only send one receipt, but if the unread message is duplicated, you can send one for each unread copy. Once a message is read, you can't easily re-generate a receipt. (You would need to use OutlookSpy or MFCMapi to reset the receipt flag.)
Is the shared mailbox connected as a secondary mailbox or using POP3? Generally speaking the copy in a secondary mailbox should reflect the read state of the mailbox, so only 1 RR is sent, but if the user is caching the mailbox (I forget if that is possible in Outlook 2003) and working offline, a second RR could be sent.
POP3, because it downloads a copy, could result in a second copy.
Yes, it can be due tocached mode, but outlook should sync changes immediately, so if it is due to cached mode, the cache file is corrupted. Delete the ost file and let outlook make a new one - assuming you can identify the problem computer that sent the second receipt.
if it happened because the mailbox was set offline all these months, then the ost file is not corrupt.