Ah, so it is the same problem? The original post in this forum was because the mailhost probe failed. Having read the response, I agree that in the headers of that probe that the secondary MX did not show the IP address of the spamcop mailer which sent the probe. The post in help was the result of a spam report where all of the received lines show an IP address, so it did not look to me as though the explanation for the first problem applied to the second - leading me to think it is a different problem. I am sorry if I was wrong.
As most legitimate email comes to the primary MX, about 90% of the mail I receive via the secondary is spam so it will be a pity if I cannot report mail received from via the secondary MX.