Outlook not retrieving new messages

[tonkajeep34]

Hello,

I've got a remote user that is setup as a cached mode outlook 2003
client to a Exchange 2000 server. It's been working fine however just
the other day he noticed that it stopped downloading new messages.
It'll still send messages just not retrieve the new ones.

I had him uncheck cache mode close, open outlook and then recheck it
and everything seemed fine, however 2 days later it's doing it again.

Could the OST be corrupted? i'd hate to have him delete it and recreate
as his mailbox is almost 2gb and it'd take a while over a t1.

thanks,
Mike