> > I've just discovered something rather interesting after I enabled the > msa_networks feature in local.cf. What's happening is this: > > 1/ spam arrives at the sendmail box from someone who has used a > non-existent email address in our domain > > 2/ spamassassin clearly marks this as spam, sendmail adds the necessary > headers, modifies the subject and relays to exchange > > 3/ if exchange is configured to send a copy of received email to an > external account OR the message is destined for a non-existent mailbox, > exchange will initiate a connection with sendmail either for forwarding > mail or for NDR > > 4/ since the exchange box is now trusted via msa_networks, the email > receives a clean bill of health from spamassassin and sendmail proceeds > to remove the headers previously added for the incoming message except > for the subject line which is left with the previously changed header! > > How can I tell sendmail milter not to remove any of the headers as the > email message is really still spam??? > > Although we could drop all spam and forget about this whole issue, > company policy dictates that any email destined to an existing recipient > mailbox will be delivered be it spam or not (false positives in the past > have left many weary of lost email)! > > > Cheers, > AK.
AK, The MTA should not accept email for non existent email addresses - rh
