[Exim] requested code return

Hi All,

          I have been using exim for a little while now, all is going
well.  I was wondering if version 4.x supports the returning of SMTP
code status 551 ("User not local: Please try <forward-path>").  I have
checked the on-line documentation on how to do this, but can not find
any related information.

Can anyone suggest a method in which to do this (or point me to the
required docs)?

Thanks in advance,
                              Andrew.