I am running Exchange 2003 Enterprise SP2 on a Windows 2003 R2 server. I have about 15 users on this server who use Outlook 2003 SP3 in cached Exchange mode as an email client. One user has a rather large mailbox according to Exchange System Manager but this does not appear to be the case from the user's interface. ESM has been saying that this user's mailbox is more than 2.3 GB with more than 32,000 items for months now. Since the system limits are set to issue a warning at 1,048,576KB, this user gets an email daily indicating that his mailbox is too large.
The user claims he has archived data appropriately and should no longer receive the email. When I look at the user's mailbox via Outlook Web Access and via his Outlook client I agree that it does not appear that this user has 32,000 emails, notes, calendar items, etc. In my opinion this mailbox's true size should be much smaller than what ESM reports.
Running the Mailbox Manager in report mode shows this user having 3029 items which is far more believable. I would like to reduce the size of this users mailbox according to ESM. If the items really are there I would like to find a way to see all of them so we can clean them up. If the items are not there, I would like to make ESM report the correct size of this mailbox.
I have verified that the nightly backup processes are running and completing normally (Full backups on Monday nights; Differential backups Tuesday Sunday; System State backups nightly). I have also verified that Event Codes 1206 and 1207 (the mailbox store cleanup start and complete messages in the Event Viewer) are running and completing normally. Item retention is set to 7 days, the option Do not permanently delete mailboxes and items until the store has been backed up is not enabled.
Yesterday I ran an offline defrag of the mailbox store. While it shrunk the database by a bit more than 1.5GB, it did not help the size of this users mailbox.
Some history: Prior to implementing Exchange Server all users had a POP3 account that ran on a different email host software (SmarterMail). The .pst files from those accounts were imported to the respective user's Exchange account. Following import, an archive.pst file was set up for each user on their respective PCs.
Some specifics to this user: This user's PC has been replaced and his archived mail .pst file was imported to Outlook personal folders on his local machine. Presently the archive.pst file in question is less than 1 GB (827MB) and the current .ost file is about 159MB. I have checked the data file location to be sure that there are no other data files lurking out there, his archive.pst file is the only data file showing.