[Dshield] PDF Spam Wave

Tom dshield at oitc.com
Thu Aug 9 15:27:10 GMT 2007

At 10:47 AM -0400 8/9/07, Valdis.Kletnieks at vt.edu wrote:
>In today's environment, the Right Thing To Do is to reject the mail *inband*
>while the connection is open - send back a 4xx or 5xx reply for the MAIL FROM,
>RCPT TO, or DATA commands. If you never '250 OK' it, you're not 
>responsible for
>generating a bounce - that becomes the responsibility of the machine that's
>trying to feed you the mail.


I beg to slightly differ.  If you know you want to reject, send a 
5xx. To many servers are sending 4xx when they really mean 5xx. 4xx 
just causes a valid mailserver to continue to retry thus delaying the 
proper handling of mail that was truly rejected by the recipient.


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