I have an Accounts payable Shared mailbox used by 5 users.The shared mailbox wills top receiving mail for some users others it will not send ( it leaves the messages in the outbox) others will delete or move certain messages but when they do this others cannot see that this has been done and will see the deleted/moved messages still in the INBOX.All other shared mailboxes for other users worked correctly.
I managed to fix this using the MS KB article - Synchronization problems occur in Outlook and in Outlook Web App Specifically, the following steps resolved the issue: 1. It can take some time for folders to resync after rebuilding the OST, especially if the profile is large. And how big is the "primary" mailbox, do you have any other shared mailboxes added? @Vasil, yes there are other shared mailboxes attached.It's nearly two days now without updating, so don't think it's a time issue. The old OST was 11GB and i know the missing shared mailbox data is about 2GB.To do this open the mail profile settings in Outlook and click More Settings.On the Advanced tab, uncheck "Download shared folders".