Strange MX Record for altavista.com

[Barry Finkel]

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