Derek B. Noonburg wrote:
> I'm running postfix to handle email for several users. One of them
> has a .forward file that points to a gmail address. Gmail's servers
> are rejecting some email for various causes ("low reputation of
> sending domain", SPF failures).
Yes. And that might occur for both validly spam messages as well as
invalidly non-spam messages.
> The problem is that postfix then bounces the email back to the (likely
> forged) sender, which means my server is sending backscatter.
In the case of validly rejected spam.
> What I'd like to do is silently drop any email that's rejected by the
> target of a .forward file. Is there some way to configure postfix to
> do that? Or some better way of handling this problem?
>
> Thanks in advance for any advice.
I can only tell you what I do in the case of a similar situation here.
Here I forward using procmail. In the ~/.procmailrc file I have the
following.
:0
* ^From: .*MAILER-DAEMON
bounces/
This catches all of the bounces such as rejections from Google. These
are saved into a bounces folder. And then I have a cron job that
sends notifications if there is new mail arrived in bounces so that it
can be handled manually. Since that mail may be either non-spam or
spam and in the non-spam case it should not be lost in the mist. And
in the spam case it needs to be used to train the anti-spam filter.
Also if you are seeing many actual validly spam messages rejected then
that says that your anti-spam filtering is not tuned up sufficiently.
Sure there will always be a small false negative rate. But it should
be a very small rate.
Setting up and configuring anti-spam is the topic for a different
mailing list. But if mailing to Google's Gmail this is required to be
fully active and tuned up or your reputation for spam will suffer due
to the passing through of it. I am using combined arms tactics with a
combination of CRM114 and SpamAssassin and find the result good.
Bob
