Tilman Schmidt wrote:
Am 28.02.2013 23:52, schrieb John R Pierce:
you can't parse the headers until you read them, and you can't read the headers until you accept the incoming message.
Not true. You can read the entire mail in the SMTP DATA phase and still reject it after the terminating single dot. Works perfectly fine on several MIMEDefang installations I set up to reject incoming mails containing malware or exceeding a certain SpamAssassin score.
Right, I meant to respond to that, but forgot before I got home.
Look, somehow, someone, somewhere, has to decide they're receiving spam from an address... and the question is, *what* address. By trying to block what are allegedly "open relays", they're *also* blocking very large hosting and service providers, *all* of whose mail goes through that gateway. What *should* be reported to be blocked is the domain that's sending the spam.
Blocking an open relay should be done *only* on human investigation, to see whether that's the majority of what's coming out of there, and consideration of what the "relay" is, whether it's a known source, or an innocent large provider.
mark