[Exim] Is there something wrong with his message?

Hello,

I set up a system filter with an if statement containing fail text
"something" and seen finish. I have an alias file defining all mail to
postmaster belong must be sent to another user, let's say it's called
for example joe.

My filter captures messages I want it to do, and it even sends the failure
messages to postmaster, and they get even forwarded OK. The thing I'm
wondering whether the following at the begining of the failure messages is
OK:

--- cut ---
A message sent by

<>

could not be delivered to one or more of its recipients. The following
address(es) failed:

  postmaster@???
    This message may contain the nimda worm!

--- cut ---

And then comes copy of the original message.

Any ideas?

    Regards, Petri