The following error is logged in a ESM wlog file:
Subject: Good Morning
Checksum: 629c19b9-2535-adb8-c08a-b774e9e1a080 (gen-header;3.8)
DEBUG: BEGIN GetCheckSum()
DEBUG: calling GetProps for property 007D001F
DEBUG: END GetCheckSum() - result 0
Error: Unknown Error.
Component: Microsoft Exchange Server Information Store
Low level error: 800CCE05
This error is caused by corrupt or missing attachments in the mail as it resides in Exchange, usually the attachment will have been removed by Anti-Virus software due to being infected.
As the mail is infected, locate the mail in the users mailbox and delete it.