Exchange 2010 : Useful Logs
The following logs on Exchnage 2010 CAS/HT and Mailbox Servers (logs vary between role division) are available to aid troubleshooting:
C:\Program Files\Microsoft\Exchange Server\V14\Logging\AddressBook Service\AddressBook*
C:\Program Files\Microsoft\Exchange Server\V14\Logging\Imap4\IMAP4*
C:\Program Files\Microsoft\Exchange Server\V14\Logging\Pop3\POP3*
C:\Program Files\Microsoft\Exchange Server\V14\Logging\RPC Client Access\RCA*
C:\inetpub\logs\LogFiles\W3SVC1\u_ex*