Hi Len,
thank you very much for detailed description.
So I'll check fetchmail to get only the local mails.
Best regards
Christian
Len Budney wrote:
> Christian Wiese <[EMAIL PROTECTED]> wrote:
> >
> > [our Qmail SMTP HUB]
> > 1. Fetchmail fetch the mail from POP3 mailbox at our ISP
> > 2. The HUB transfers the mail to our internal Qmail server.
> >
> > [internal Qmail server]
> > 3. our internal Qmail server delivers the mail into the local mailbox of
> > "mailuser", but there are still messages that the qmail server can't
> > treat local
> > 4. the internal qmail server transfers the outgoing messages back to HUB
> >
> > [HUB]
> > 5. outgoing messages will be transferd via maildirserial to our ISP's
> > SMTP server
>
> This is the fault of fetchmail. More specifically, you're using fetchmail
> wrong. It has nothing to do with using "To:" instead of "Cc:" at all.
>
> You're letting fetchmail forward popped mail through qmail, to all of
> the recipients in the headers. But that's exactly what the original,
> remote sender already did! So you're letting your mail server do
> something which is properly none of its business.
>
> Your only real option, if you want to use fetchmail in this setting,
> is to do one of the following:
>
> 1. Scan the email's headers for specific local users addresses. This
> is hard; in fact for mailing list emails or BCC-ed emails, it is
> basically impossible. (If your ISP uses qmail, then you can do it
> after all, since qmail writes the envelope at the top of every
> message.)
>
> 2. Give each local user a separate POP account at your ISP; run
> fetchmail separately for each user. Deliver to that specific
> user. This prevents you from using mailboxes with addresses like
> user+extension@ or user-extension@, which is a major bummer.
>
> Since most mailers discard envelopes (or record them in a hard-to-parse
> way), you will have big problems mixing a push-protocol (SMTP) with a
> pull-protocol (POP3).
>
> A better alternative is to get your ISP to set up AutoTurn for your
> maildrop. In that scenario, it is the ISP's problem to keep all mail
> envelopes straight. All you have to do is perform the local delivery.
>
> Len.
>
> --
> You're deluding yourself if you think that these anti-reliability
> features actually affect the spammers.
> -- Dan Bernstein
