Help - Name server timeout

[Will Yardley]

Simon Dullingham wrote:
> I have been having trouble with my own ISP being able to send mail to my
> company's domain. Occasionally things get through, but in general I get a
> "Name server timeout" message, and after 5 days the email gets returned as
> undeliverable.
> 
> I have upgraded sendmail to 8.11.5 and BIND to 9.2.0, rc1  to see whether
> that solves the problem, but I still seem to have a problem. I am trying to
> send from @austin.rr.com to @fantoft.com. 

there is no A record for that domain.  i believe that sendmail by default
won't send mail to, or receive mail from, domains that don't have an A record
that resolves.  there are some options in sendmail to not canonify sender and
/ or recipient domains, or not to make sure that the sender / recipient
domain has an A record.  the simple thing to do if you have control over your
domain's DNS is to add an A record; this is really a sendmail configuration
problem though rather than a DNS problem.

you could try something like this 
CANONIFY_DOMAIN(`yourdomain.com')
FEATURE(`nocanonify', `canonify_hosts')dnl
(note - this will also disable canonification so if you're not using the
machine running sendmail purely as a mail gateway you might want to figure
out some resolver options to add to the sendmail configuration rather than
using nocannonify).

for incoming mail, you can use:
FEATURE(accept_unresolvable_domains)

jazz% dig fantoft.com

; <<>> DiG 9.2.0rc1 <<>> fantoft.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28586
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;fantoft.com.                   IN      A

;; AUTHORITY SECTION:
fantoft.com.            10800   IN      SOA     raptor.fantoft.com. root.fantoft.com. 2000121449 10800 3600 604800 86400

;; Query time: 948 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Aug 17 14:34:07 2001
;; MSG SIZE  rcvd: 77


-- 
Sintax error in config file! (line 378)
aborted!