Strange MX Record for altavista.com

[Mark Andrews]

> There is a mail system here that has mail queued for altavista.com.
> dig reports:
> 
> atalanta% dig altavista.com mx
> 
>      ; <<>> DiG 8.3 <<>> altavista.com mx 
>      ;; res options: init recurs defnam dnsrch
>      ;; got answer:
>      ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
>      ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 5, ADDITIONAL: 0
>      ;; QUERY SECTION:
>      ;;      altavista.com, type = MX, class = IN
>      
>      ;; ANSWER SECTION:
>      altavista.com.          10M IN MX       0 .
>      
>      ;; AUTHORITY SECTION:
>      altavista.com.          10M IN NS       ns4.yahoo.com.
>      altavista.com.          10M IN NS       ns5.yahoo.com.
>      altavista.com.          10M IN NS       ns1.yahoo.com.
>      altavista.com.          10M IN NS       ns2.yahoo.com.
>      altavista.com.          10M IN NS       ns3.yahoo.com.
>      
>      ;; Total query time: 65 msec
>      ;; FROM: atalanta.ctd.anl.gov to SERVER: default -- 146.137.64.5
>      ;; WHEN: Wed Sep  1 16:27:21 2004
>      ;; MSG SIZE  sent: 31  rcvd: 142
>      
>      atalanta% 
> 
> That is a strange MX record.  When that mail system (MX Exchange)
> tries to send the mail, it opens an SMTP port 25 connection to one of
> my DNS servers.  Is this what is supposed to happen?  Thanks.
> ----------------------------------------------------------------------
> Barry S. Finkel
> Computing and Instrumentation Solutions Division
> Argonne National Laboratory          Phone:    +1 (630) 252-7277
> 9700 South Cass Avenue               Facsimile:+1 (630) 252-4601
> Building 222, Room D209              Internet: BSFinkel at anl.gov
> Argonne, IL   60439-4828             IBMMAIL:  I1004994

	It's an attempt to say "don't sent mail to the domain
	altavista.com."  It's a pity it is not been codified
	AFAIK.

	I would be teaching my MTA to treat a MX record like
	this as a indication to just bounce the mail.

	Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org