MX problem

[Sumit Mehrotra]

Hello BIND users.

I have been running an authoritative DNS on my machine(dhruv.coptic.net/dhruv.bu.edu) for a domain coptic.net( which resides on a different machine, pharos.bu.edu ( and even on a different subnet). The name resolution is fine. I face a problem when I send an e-mail to user in that domain. The returned mail is attached at the end. 

a dig on the NS for the MX record seems to be fine. :

~ % dig @dhruv.bu.edu coptic.net mx

; <<>> DiG 8.2 <<>> @dhruv.bu.edu coptic.net mx
; (1 server found)
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2
;; QUERY SECTION:
;;      coptic.net, type = MX, class = IN

;; ANSWER SECTION:
coptic.net.             1H IN MX        10 mail.coptic.net.

;; AUTHORITY SECTION:
coptic.net.             1H IN NS        dhruv.coptic.net.

;; ADDITIONAL SECTION:
mail.coptic.net.        1H IN A         128.197.10.20
dhruv.coptic.net.       1H IN A         128.197.14.80
;; Total query time: 2 msec
;; FROM: csb to SERVER: dhruv.bu.edu  128.197.14.80
;; WHEN: Tue Jan  9 23:59:04 2001
;; MSG SIZE  sent: 28  rcvd: 101


The MX query, I understand is resolved as the chain admin at coptic.net->coptic.net(MX)->mail.coptic.net->128.197.10.20.

The host 128.197.10.20 however does not accept the mail. And according to the error, I figured it might be becasue of the host not recognizing that it is supposed to accept the mail for coptic.net domain. The host physically resides in the bu.edu domain.

 Can this be corrected by adding Cw coptic.net to the sendnail.cf file?
Prior to this there was another NS ( owned by Network Solutions) which was doing the same thing, I cannot figure how that set up was working with respect to e-mails?

Thanks

- Sumit

----------------------------------------

Bounced E-Mail.

The original message was received at Tue, 9 Jan 2001 23:31:50 -0500
(EST)
from RELAY1.BU.EDU [128.197.27.99]

   ----- The following addresses had permanent fatal errors -----
<digest at coptic.net>

   ----- Transcript of session follows -----

553 mail.coptic.net. config error: mail loops back to me (MX problem?)
554 <digest at coptic.net>... Local configuration error

    [ Part 2: "Delivery Status" ]

Reporting-MTA: dns; pharos.bu.edu
Received-From-MTA: DNS; RELAY1.BU.EDU
Arrival-Date: Tue, 9 Jan 2001 23:31:50 -0500 (EST)

Final-Recipient: RFC822; digest at coptic.net
Action: failed
Status: 5.5.0
Remote-MTA: DNS; mail.coptic.net
Last-Attempt-Date: Tue, 9 Jan 2001 23:31:50 -0500 (EST)
-------------------------------------------------------------