how to stop send and receive for user

Hi,

please help me on this,

In our organization some user's goin to retire,so customer given some requirements

1) user account should not be disable after user retirement.

2) user want to view their mailbox after their retirement.

3) user should not able to do send and receive after their retirement.customer want to stop send and receive for retirement user mailbox.

4) customer required NDR report when someone send mail to that retirement user mailbox.NDR report should be like this The e-mail address you entered couldn't be found. 
   Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk.

   Here we are using Exchange server 2010 version 14.2.....

   without disable user mailbox can we do above requirements ???????????


  Here we are using Exchange server 2010 version 14.2.....