how to inactivate the account and also want to look at previous email history of user through exchange server 2013?

There is no such thing as an inactive account in Exchange.

You can disable the underlying AD account, which will leave the mailbox operational. Then to view the content you will need to grant yourself full mailbox access. The content cannot be viewed on the server itself unless through OWA.

If you want the server to bounce email, then adjust the mail delivery options so it rejects email from everyone.

Simon.

Hi,

For more information about disabled mailbox, refer to this document.

https://technet.microsoft.com/en-us/library/bb232039%28v=exchg.150%29.aspx

My suggestion is to use the New-MailboxRestoreRequest cmdlet to merge the contents of the disabled mailbox with an existing mailbox.

https://technet.microsoft.com/en-us/library/ff829875%28v=exchg.150%29.aspx

Best Regards.