[cobalt-users] Re:Changing CName and such

[Charlie Summers <charlie@xxxxxxxxxx>]

At 1:28 PM -0400 5/22/02, Mike At Spy is rumored to have typed:

> Does anyone know what the proper set-up on a RAQ4r would be if one wanted to
> get email from somewhere else?

   That isn't what you want to do; what you MEAN to ask is, "what is the
proper setup to have a different machine handle his email?"

> The customer wants an unbelievable number of
> email addresses, and while he will be hosting with us, he wants the Cnames
> and such changed so the mail is through a different service (but still reads
> as his domain name).

   Why in the world would you "change" canonical alias names, when you really
want to point his Mail eXchanger record to...well...his mail exchanger?

   Assuming you are handling main and secondary DNS for this client's domain
(might be something you want to subcontract, based on this question), set up
an A record for mail.whatever.tld pointing to the fixed IP of his mail
exchanger, set up an MX record pointing to mail.whatever.tld, make sure your
name servers are listed in the whatever.tld domain record, and you're done
(it's his problem to make sure his machine accepts mail for whatever.tld as
local, not yours; all you have to do is announce to the world that
mail.whatever.tld is the one to talk to). Avoid cname records in DNS unless
you know _exactly_ why you want to use a cname record instead of an A record
(hint: practically never, but sometimes).

   If he wants a "service" (like everyone.com) to handle his email, ask
_them_ specifically what you should set up in your DNS, since it's likely in
that case you'll need _multiple_ MX (or even multiple A) records attached to
the domain with differing preference values. They might even, in this case,
have you set your machine as the lowest-preference MX (highest number) just
in case they are completely unreachable. I wouldn't do it, but it's your
client.

   Of course, it's advised you use the GUI to make these changes to the DNS
records, for reasons hashed out here a gadzillion times before. (Never mind
that it would actually be faster to do it manually, the "secret sauce" _will_
splatter your tie and drip on your shirt if you don't use the GUI.)

   See:

http://www.isc.org/products/BIND/docs/bog-4.9.4/bog-sh-5.html

   ...for a reasonable overview of record types and usages.

         Charlie