MISSING SENT EMAILS IN OUTLOOK - EXCHANGE 2010

Are the deleted emails the oldest in the sent items folder?
Are all the deleted emails for all users the same sent date range?

Are the users in question using mobile devices that use Exchange Active Sync?

this particular user is right now missing december 11 to yesterday.  i have not checked other mailboxes.  this user does not use a mobile device.  i will check a few other mailboxes.

When the user sends an email, does it actually get saved to the sent items folder?

Check options.
File / Options / Mail - Save messages - Save copies of messages in the Sent Items folder

Does the user only have one mail profile in Outlook?

yes, it is a basic exchange/outlook setup with no modifications.  a single profile

i check s few mailboxes.  I have not seen another occurrence of the same issue yet. no errors on the server

Is there any Archving set in Outlook or any Rule ?

If its one user try to move his mailbox and then Export the rules from Outlook and then open Outlook with /Cleanrules and check

- Rancy

no archiving, no auto cleaning rules.  can anyone think of a cause?

I have been informed this has happed to a few others, but not everyone.  just large blocks of email go missing from SENT folders. this sia fairly new install of Exchange, no other know issues.  Exchange 2010 on Win 2008 64 on an ESXI 5 host.  90 users, 160GB of mail storage, plenty of disk space.  12 GB RAM.  all other functions work well.

i will try