RE: blowback, was A new SMTP "3821" [Re: FTC stuff...........]

On Mon, 3 Jan 2005 [email protected] wrote:

> 
> Dean Anderson wrote:
> > The blowback issue is different from this.  Blowback happens whenever
> > anyone _rejects_ emails based on SPF.
> 
> Fair enough
> 
> > A bounce is generated from the relay to the forged sender.
> 
> Is it?  If the receiving MTA issues an SMTP reject command, it does not
> assume any responsibility for the delivery of the mail.  It will
> therefore not generate a spurious bounce message.

This isn't how most current SMTP servers behave.  
(Sendmail/Qmail/Postfix/Exchange, anyway)  If the receiving MTA rejects 
mail, the sending MTA generates a bounce to the sender.  The sender of 
course, can be forged.

> If the sending MTA generates a bounce message, then it's likely not a
> virus or other malware likely to forge a sender address.

???

This too is wrong. Many viruses send "forged" bounces containing a virus. 
One cannot assume that because you opened a bounce, the message will not 
contain a virus.  Further, a genuine bounce with an undelivered message 
may contain a virus in the undelivered message.


> Matthew.van.Eerde (at) hbinc.com                 805.964.4554 x902
> Hispanic Business Inc./HireDiversity.com         Software Engineer
> perl -e"map{y/a-z/l-za-k/;print}shift" "Jjhi pcdiwtg Ptga wprztg,"
> 
> 
> 

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