[exim] Sender Verification to MS Exchange

Hi all

I have exim as a front-end server and exchange 2003 sp2 as a backend system. Not sure if SP2 is related - but I am getting problems sending email to certain recipients. I have tried telneting to the mail server in question and it accept verification if I use an email address that the exim server handle, but doesn't when the lookup needs to be made to the exchange server.

I thought sender verification was working after implementing a solution found a couple of years ago:

http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20040405/msg00075.html

It seemed to work at the time!! I have the following in exim config:

  ### Performs sender verification on Exchange Server ###
  deny  domains = **********.org
       !verify = recipient/defer_ok/callout=no_cache
  #######################################################

and

special:
  driver = manualroute
  transport = remote_smtp_nofb           
  domains = ***.org
  route_data = nt-**-h1.gd****ee.h**
  no_more

Any help would be much appreciated.

Kind regards

Gordon