Really wierd glitch in resolution

[Cricket Liu]

> This question is part mail based, part DNS based, but its the DNS
> thats throwing me.
> 
> I manage several majordomo lists, and one in particular is giving me
> gripe.  A user with an address at hcc.mass.edu is subscribed to the
> list.  However, when I send a message to the list, I get back an error
> that the user @hoc.mass.edu cannot be delivered to, because
> hoc.mass.edu does not exist.  I have used dig several times on
> hoc.mass.edu, and only get back the SOA for mass.edu.

Is it hcc.mass.edu or hoc.mass.edu?  hcc.mass.edu seems to exist:

$ dig mx hcc.mass.edu.

; <<>> DiG 9.1.1rc2 <<>> mx hcc.mass.edu.
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44791
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 3, ADDITIONAL: 6

;; QUESTION SECTION:
;hcc.mass.edu.                  IN      MX

;; ANSWER SECTION:
hcc.mass.edu.           43192   IN      MX      10 graygull.hcc.mass.edu.
hcc.mass.edu.           43192   IN      MX      20 hightide.hcc.mass.edu.
hcc.mass.edu.           43192   IN      MX      15 beach.hcc.mass.edu.

hoc.mass.edu doesn't.

cricket