John Peacock wrote:
That's the part I don't understand. What do you hope to accomplish with qpsmtpd
post-queue? The whole point of qpsmtpd is to be a fully compliant SMTP engine
with a flexible plugin architecture. It's designed to be a replacement for
whatever process handles the inbound SMTP transfer. qpsmtp can handle
antivirus, RBL-style blocklists, validation of FROM: and TO:, etc.
In order to insert a content filter into Postfix the filter
must converse with Postfix in SMTP. The backend of the
filter also speaks in SMTP unless the the plugin
postfix-queue is used. It is/was our intention to create
a plugin that will operate on the body of the message not
as an anti-virus or anti-spam device but
provide a different beneficial service.
As I mentioned before, email containing viruses or spam email
will have already been removed in a pre-queue filter, which
might in fact be qpsmtpd.
"Failures" during the filter processing will require notifying the sender.
This is a very bad idea. If you have already accepted the messages, you no
longer have the ability to refuse them during the SMTP transaction and can only
bounce them. The vast majority of spam is sent with forged FROM: and/or
envelope sender, so it is not acceptable to notify the sender via a bounce,
since you are simply annoying an innocent bystander.
No, this is a VERY GOOD idea. I will be using a qualified
SMTP package to converse with Postfix minus of course XFORWARD.
I have no intention of bouncing forged email as I expect
none to arrive within our MTA core due to pre-queue filtering
as mentioned above. "Failures" from above are not forged
FROM: and TO: envelope sender discoveries.
Your training/mindset is spam & virus email for good reason.
The origins and primary use of qpsmtpd is anti-virus and
anti-spam. The qpsmtpd package has accomplished a lot in
that arena. My thoughts are aimed at providing a benefit
to those who are "real" users of our mail system.
I want to use qpsmtpd as an SMTP wrapper around our
intended application in order to insert it into
Postfix. If Postfix did not require an SMTP interface
for the content filter I would not be considering
the use of qpsmtpd.
Isn't it nice to think of a product that you have produced
or contributed to as having more applications than you
initially intended.
I doubt if individuals that helped create the Internet
realized all the good applications that came from their
work later but I can imagine that they felt good about
it.
Now that I think of it, someone within the qpsmtpd
community must have considered using the package as
a Postfix content filter since there is a postfix-queue
plugin. Good for them! Wish they would stand up and
help me out on this one.
