Can anyone help?

I have a client that uses Exchange 2000 (latest SP). One of the users
has complained that they send e-mail and they do not appear in the Sent
Items folder (Outlook 2003 SP2).

This is not the case for anyone else.

This does not happen to every e-mail, just once in a while.

I chacked setting, view settings set to Sent To, which is correct.

I deleted and recreated his profile as well as Outlook profile, gave
him a new PC, but problem still persists.

He tells me it seems to happen when he e-mails an external address and
CC's someone in from Global address list (within the office).

I have a printout of the e-mail which was CC'd to an internal recipient
and I have exhausted all possibilities to fine the e-mail in the
mailbox. (I done an advanced find at top mailbox level).

There are no Outlook rules set up for the user. I cannot replicate the
problem myself, however, it has happend a few times this year, so I
know it is still happening, also I have the printout as mentioned
above.

I have turned on Retain Deleted Messages on Exchange for 7 days, so if
it is being auto deleted, but I don't have much hope of finding
anything out here.

There are no Exchange errors as well as I defragged the database and
ran the ISINTEG tools on it 2 weeks ago.

I would apreciate any help from you guys.

Many thanks,

Sanjay