[time-nuts] Strange reports of bocked messages to timenuts

Mike S mikes at flatsurface.com
Sat May 17 14:52:59 UTC 2008


At 06:55 AM 5/17/2008, John Ackermann N8UR wrote...
>I think this is some sort of weird backscatter problem; I've never 
>seen
>this message before.
>
>But I've unsubscribed this joconnell person in the hopes that will 
>stop it.

It will, but the root problem is at febo.com (failure to follow RFCs), 
which is resulting in message rejection and a bounce back to the 
Reply-To: addresses (including time-nuts at febo.com).

> > WHY DID THIS HAPPEN ?
> > =====================
> > 550 ######## DNS RHS BLACKLIST: http://www.rfc-ignorant.org 
> ########

If you follow the link and look up febo.com, and find that 
"ns1.febo.com reports that febo.com has an MX (meow.febo.com) which 
ns1.febo.com says is a CNAME (to febo.com)"

RFC1912 says:

    Don't use CNAMEs in combination with RRs which point to other names
    like MX, CNAME, PTR and NS.  (PTR is an exception if you want to
    implement classless in-addr delegation.)  For example, this is
    strongly discouraged:

            podunk.xx.      IN      MX      mailhost
            mailhost        IN      CNAME   mary
            mary            IN      A       1.2.3.4

    [RFC1034] in section 3.6.2 says this should not be done, and 
[RFC974]
    explicitly states that MX records shall not point to an alias 
defined by
    a CNAME.

But that is exactly what febo.com is doing:

dig -t MX febo.com
...
;; ANSWER SECTION:
febo.com.               495834  IN      MX      10 meow.febo.com.

dig meow.febo.com
...
;; ANSWER SECTION:
meow.febo.com.          573937  IN      CNAME   febo.com.
febo.com.               193364  IN      A       24.123.66.139

Having said that, the system which is doing the bouncing (conwin.ie) is 
brain-dead and doing something even worse - sending the bounce with no 
From: header (I assume, since my email server ends up putting a local 
From: on it to make the message RFC legal).





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