[CentOS] sendmail question

Wed Oct 21 18:40:35 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Jerry Geis wrote:
>>
>> /
>> You still haven't answered how long nslookup takes to respond with these 
>> or your IP addresses.  I think sendmail will ask DNS for an MX record 
>> first because that's how mail is supposed to work - then if that fails 
>> it goes for an A record or your hosts file.
>>   
> Sorry - missed that one .
> 
> nslookup cnn.com comes back fast.
> 
> if I do nslookup mymachine.domain.com it comes back with error.
> 
> How do I make this resolve faster or something. I have no way to make an 
> MX record
> for this box. its all just local email. it never leaves the box.

An error that is returned quickly isn't a problem - a timeout of many 
seconds is a problem.  How long do the failing responses - and for your 
IP addresses and 127.0.0.1 take?

The cleanest approach is to run a local nameserver that is primary for 
your local domain (even if it is not official) and your local network 
ranges and caches for everything else.

-- 
   Les Mikesell
    lesmikesell at gmail.com