Re: No DNS consistency checks in Debian spam filter?
On Tue January 8 2008 13:30:22 John Hasler wrote:
> Mike Bird writes:
> > No, I checked headers during the flood. Debian was forwarding spam
> > directly received from hosts with PTR records without matching A records.
>
> That just means it doesn't use your favorite method (because many ISPs have
> broken DNS).
Hmm, I'm postmaster and maintainer for quite a lot of Linux mail servers,
mostly Debian/Postfix and some Fedora/QMail. Several years ago when we
started enforcing consistent rDNS we'd get about one complaint per month
related to ISPs with broken rDNS. I don't think we had any such complaints
in 2007.
If in 2008 Debian is not enforcing rDNS consistency checks at SMTP-connect
time then Debian is doing a poor job of blocking spam. Worse - Debian is
unnecessarily relaying millions of spams per day. Once relayed, those spams
become much harder to block.
Please reconsider.
--Mike Bird
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