David F. Skoll wrote: > [EMAIL PROTECTED] wrote: > >> No need to be condescending about it. I have no problem taking it off >> list and explaining how you are mistaken. > > OK, look. I guess I need to spell it out for you. > > End-user PC has virus. Virus does this: > > telnet isps-smtp-server 25 > HELO bogus > MAIL FROM:<[EMAIL PROTECTED]> > RCPT TO:<[EMAIL PROTECTED]> > DATA > . > > Then ISP's mail server does this: > > telnet victims-smtp-server 25 > HELO isps-smtp-server > MAIL FROM:<[EMAIL PROTECTED]> > RCPT TO:<[EMAIL PROTECTED]> > DATA > . > > If victim's SMTP server fails the DATA with a 5xx code, then > backscatter goes [EMAIL PROTECTED] > > Understand now? >
Sounds like the isps-smtp-server operator has a problem of accepting responsibility to forward mail that may be undeliverable. dp _______________________________________________ Help us build a comprehensive ClamAV guide: visit http://wiki.clamav.net http://www.clamav.net/support/ml
