Re: Sendmail and fetchmail problem
On Sep 15, staf wagemakers (staf@digibel.org) wrote:
> On Fri, Sep 15, 2000 at 02:14:49PM -0400, John Ackermann wrote:
> > In message <[🔎] 20000914194158.A1952@digibel.org>, staf wagemakers writes:
> >
> > >You could add the next line to your /etc/mail/sendmail.mc
> > >
> > >FEATURE(accept_unresolvable_domains)
> >
> > I regularly see "domain must resolve" messages in my logs, usually from
> > random sites Out There. Is there a significant security/spam risk in
> > accepting unresolvable domains? I have the antispam stuff (no relaying,
> > etc.) turned on in my sendmail.mc already.
>
> Normally you don't want to accept mail from non-valid domains, all from
> addresses should have a valid internet address. I don't think your mailserver
> get a open relay by enabling this "feature" but I wouldn't use it on a
> mailserver that is connected to the internet.
>
> You can't reply to message because it comes from a non-existing domain, so
> why would you waste time to read it :)
I agree with all of the above, but have an answer to the last question
:-) If you are retrieving mail from your ISP via fetchmail and
sendmail, presumably the domains were resolved by your ISP's MTA. So,
why bother resolving them again? I get mail this way on my laptop,
and I don't want to have some message not delivered to my laptop
because the sender's domain temporarily cannot resolve.
--
Neil L. Roeth
neil@occamsrazor.net
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