DNS local zone

[Kevin Darcy]

freightcar at gmail.com wrote:
> I am using bind and I am trying to setup local zone for local computer.
> I would like to be able send emails to user at monitor - this is the zone
> file
> $TTL  86400
> @       IN      SOA     monitor.  email.monitor. (
>                               3         ; Serial
>                          604800         ; Refresh
>                           86400         ; Retry
>                         2419200         ; Expire
>                          604800 )       ; Negative Cache TTL
> ;
>                 NS      ns
>                 MX 10   mx
> ns              A       192.168.0.210
> mx              A       192.168.0.220
> monitor.        A       192.168.0.220
> when I send email to user at monitor I get an error from postfix :
> to=<user at monitor>, relay=none, delay=0, status=bounced (Host or domain
> name not found. Name service error for name=monitor type=A: Host not
> found). when I use exim I get somethig similar.
>
> however when I set  a zone mx.monitor or monitor.loc with following
> zone file - i can send mail to u... at monitor.loc and it is delivered
>
> $TTL  86400
> @       IN      SOA     monitor.loc.  email.monitor.loc. (
>                               2         ; Serial
>                          604800         ; Refresh
>                           86400         ; Retry
>                         2419200         ; Expire
>                          604800 )       ; Negative Cache TTL
> ;
>                 NS      ns
>                 MX 10   mx
> ns              A       192.168.0.210
> mx              A       192.168.0.220
> monitor.loc.    A       192.168.0.220
>
> ns requests as nslookup, dig, host will return correct answer for each
> host. why it does not work in first case?
>
>   
user at monitor is apparently not actually a legal mail address within the 
SMTP protocol. The ABNF in RFC 2821, Section 4.1.2 is "Domain = 
(sub-domain 1*("." sub-domain)) / address-literal", i.e. in DNS terms, a 
label followed by a dot, and another label, followed then by 0 or more 
labels connected by dots.

What I think is happening here is that Postfix is trying to "fix" the 
illegal address by appending something to it prior to issuing the DNS 
query, and then misreporting the error when the "fix" doesn't work. You 
could turn on query logging to see what is actually being queried from 
your nameserver.

                                                                         
                     - Kevin