Running exchange SBS 2003 with outlook 2007 clients. Have a user that does not get all of his emails delivered to his inbox. There are none in the badmail folder and message tracking says it was delivered. He is getting the message on his iphone that uses exchange activesync. Its not all messages, just every now and then, but they are business critical. His mail store is 14 gigs and he has 30k items in his mailbox. Could this be an OST or mailbox issue???