[dns-operations] can anybody think of what antispam purpose this RRset might be serving

[Paul Vixie]

colour me puzzled.  rrset ttl's are minimized by compliant initiators, so
the MX RRset here has ttl 0.  but maybe there's spamware or malware out there
that doesn't respect this, and this is the indirect way i'm hearing about it?

; <<>> DiG 9.4.0b4 <<>> @217.194.209.4 thislittlepiggy.co.uk. in mx
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40729
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2

;; QUESTION SECTION:
;thislittlepiggy.co.uk.         IN      MX

;; ANSWER SECTION:
thislittlepiggy.co.uk.  0       IN      MX      50 smtp01.hostinguk.net.
thislittlepiggy.co.uk.  43200   IN      MX      10 mail5.hostinguk.net.

;; ADDITIONAL SECTION:
smtp01.hostinguk.net.   43200   IN      A       217.194.210.206
mail5.hostinguk.net.    43200   IN      A       217.194.210.202

;; Query time: 151 msec
;; SERVER: 217.194.209.4#53(217.194.209.4)
;; WHEN: Wed Dec 20 01:42:14 2006
;; MSG SIZE  rcvd: 129