> > yes, but you are missing that this message is the answer of postgrey which is > only redirected via postfix to the client, from the view of SMTP it is 450
That's OK -- postgrey is supplying me with useful information which quickly leads me to the answer to my question: why is this message 450? > > in my opinion it would even be better not say to the delivering server that he > is greylisted - the only thing which he needs to know is 4xx and if he acts RFS > conform all is fine ________________________ I don't think it's better to give less information. The RFC's are great for the machines and the programmers, but as an admin, I want to be able to get to the heart of the problem as quickly as possible. There are many reasons why something could be 4.x.x When I read "Service is Unavailable" as an admin, I think there is a misconfiguration with the server or some other issue. These messages are there for us, not the computers, so they might as well be as descriptive as possible -- not less so. That's my opinion anyways.