Hi Guys,

we have hardly 2000 mailboxes and we are using Exchange 2010, we are looking these all mailbox should be monitored by us. like people having others user full or send as maibox access they could send email from others maibox. our requirement is we need to know who is accessing other's mailbox like that users may sent a mail without knowing other users.

Can i get these infromation on particular date and time?

Implement  Mailbox Audit Logging.

http://technet.microsoft.com/en-us/library/ff459232(v=exchg.141).aspx

Hi,
 
When we want to trace mailbox access by and delegates including administrators who have full mailbox access permissions, Mailbox Audit Logging is helpful.
 
We can also retrieve mailbox audit log entries during a specific period.
 
Here are some articles for your reference.
 
Understanding Mailbox Audit Logging
 
http://technet.microsoft.com/en-us/library/ff459237(v=exchg.141).aspx
 
Search-MailboxAuditLog
 
http://technet.microsoft.com/en-us/library/ff522360(v=exchg.141).aspx
 
Hope this helps.
 
Best regards,
Belinda