On 2008/02/08 11:35, Dave Anderson wrote: > On Fri, 8 Feb 2008, Peter N. M. Hansteen wrote: > > >Raimo Niskanen <[EMAIL PROTECTED]> writes: > > > >> If a backscatter gets through to sendmail, and it is to an invalid > >> user, what is the proper thing for sendmail to do? My sendmail > >> most probably does the default, which I guess is to bounce the mail. > > > >yes, if you receive a message intended for a non-existing user, you > >most likely bounce with 'unknown user' or the equivalent. it's the > >other end, where spam apparently gets delivered, that's making more > >noise than necessary by bouncing messages that should have simply been > >forwarded to /dev/null instead. > > While I agree with most of what you're saying, quietly dropping messages > identified as spam is _not_ the best way of handling them -- since it's > rarely possible to be 100% certain that a message really is spam, and > it's harmful to not notify the sender that a legitimate message has not > been delivered.
If you do this, and people forward mail to your machine, or you list a backup MX which accepts some spam that your machine doesn't, your policy results in backscatter to the envelope sender address. There's no right answer...
