Cisco PIX mangling: no delivery failure message?

[rpb1@cornell.edu]

Sorry to bother you with this (since I'm not a zmailer list subscriber,
though I did scan the archive before posting this), but I have a question
related to the Cisco PIX ORCPT mangling. I just recently got hit by this,
and I do appreciate the web page with the info about it, but I am
concerned that I never recieved even one error email that my messages
weren't being delivered! My understanding of mail systems is that you
should always get an error message if something fails to deliver your
message. I do get error messages for sending to nonexistant domains and
such (spammers), so I was particularly suprised to find that these errors
were happening behind my back, so to speak (caught the log error message
by chance one day). 

Anyway, is this the right behavior? Am I likely misconfigured somewhere
subtle? If not, you might want to be more careful that people do get sent
responses when delivery failures occur. 

(Not to imply that I don't appreciate all the work that's been done on
zmailer. I'm just suprised when something at that level of quality doesn't
do what it "ought" to :)

Thanks,
Robert Braddock