[Exim] Exim and Exchange

I have just joined this list in the hope that someone here may be able
to help me.

I am the administrator of an Exchange 2000 server and we are having a
problem receiving mail from Exim mail servers. The error seems to
occur coming from Exim 3.32 and 3.35 mail servers, but I con't know if
it is restricted to just those versions. Any time an Exim server tries
to send a message to our Exchange server, an NDR is returned with the
error:

This message was created automatically by mail delivery software (Exim).

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

jgaskell@???
SMTP error from remote mailer after end of data:
host mail.mgr.com.au [203.48.133.10]: 500 5.3.3 Unrecognized command


Looking through the archives of this list, this error was reported by
Silvano Sartore on 24 Jan 2002, but I can't find a solution or
explanation of the problem anywhere. The Microsoft knowledge base has
nothing on the problem. Can anyone help?

Cheers,

Joel Gaskell
MGR Consulting