Re: [Qmail-scanner-general]INCONTROLED SPAM

[Aecio F. Neto]

[EMAIL PROTECTED] wrote on 09/06/2005 22:49:27:

> Jeremy Bowen wrote:
>
> >No I'm not. Read what I wrote. "If an MTA does accept email for delivery, it
> >should NEVER bounce it"

Qmail, due to its modular architecture does accept message and decide to bounce later in its chain. You need to understand its stages in processing a message (in this order):
1) SMTP session handler (smtpd)
2) queue handlers (qmail-queue, qmail-scanner etc.)
3) delivery handlers (qmail-local, qmail-remote)

It is legitimate to bounce messages, according to SMTP RFC. It is not qmail only that bounces, but all MTAs that follows this RFC (sorry, I don't recall its number right now).

There are patches to stop bouncing by adding address verification in stage 1 (SMTP).
Look into SPAMCONTROL from Erwin Hoffman for one of them. I use it and I am very glad with it.

> >In my experience with qmail (which I'll fully admit is not
> extensive), I don't
> >believe it behaves in the manner I'm complaining about. I don't think it
> >bounces mail for unknown local users in its default configuration.

Read throughfully into SMTP RFC and you will understand that bouncing is a defined and legitimate feature in all MTAs.
Notice also, that when SMTP were defined, Internet was in its early stages (for commercial services) and bouncing was a low-effort and useful way to notify sender about non-existent users (anymore), full quota usage etc.
Bouncing now is considered harmful because high amount of spam and garbage being spread over net.
Spamcop even blocks servers that provide bounces, legitimate or not. There has been a large discussion between Spamcop founder and Qmail list that ended up with no solution - it became a religious discussin with Qmail defending RFC statements and Spamcop guy defending its "feature"...

> >If you're saying that by default qmail always accepts and then bounces mail
> >for unknown local users then I'll revise my opinion of qmail.

You should revise your opinion of using SMTP also. :-)