[Techtalk] kindergarten mail server question

[Carla Schroder]

On Thursday 21 February 2002 11:18 am, Raven, corporate courtesan wrote:
> Heya --
>
> Quoth Carla and Kai:
> > >Example: trusty Postfix server is all set up and configured at
> > >carlas.domain.com, ready to start work moving mail over the Internet.
> > > Well somewhere out there are DNS and MX thingies that have to be
> > > configured, right? Assume I can log into wherever to do all this. (in
> > > this case, my domain name registrar provides user DNS management.)
>
> 	Right.  I'm going to assume that you're using bind for your DNS
> server -- most everybody does.  If you aren't and you'd rather have the
> explanation in djbdns terms or Meta-IP terms, let me know.

O Ye of Excessive Geekiness, why would I use bind? *shudder* I'm using 
Dotster for my dns.

>
> 	There are a bunch of different sorts of records that you should
> care about.  The one you're asking about, the MX record, tells anyone
> who asks your DNS server what the mail server(s) for your domain is
> (are).  You can have more than one mail server if you want, but I'll
> keep it simple since you only mentioned one.  So, all an MX record is is
> "Mail server here!"
>
> 	You also need to know where "here" is.  So if you tell bind that
> your MX server is at mail.carlas.domain.com, it needs to know what IP
> address that is.  For this, you need an A record.  A records map names
> to IP addresses.  There are also PTR records, which do the reverse and
> map IP addresses to names.  The A records are in the zone for your
> domain, and the PTR records are usually found in the in-addr.arpa zone.
> Make sure that you have both of those in there for your new mail server.
>
> 	Omitting the A record will cause "okay, I know the name of the
> mail server, but not how to get to it, aaaaaaah!".  And DNS won't work
> for that server.  Omitting the PTR record causes more subtle failures --
> your users may have trouble subscribing to mailing lists (some mailing
> list managers check the reverse lookup of the IP a subscription request
> came from as a security feature), or using ssh or ftp to connect to the
> box (depends on their configuration whether they try to do lookups for
> that).
>
> 	There are also CNAME records, that are essentially aliases.
> "fakeout.carlas.domain is the same machine as mail.carlas.domain", for
> example.
>
> >     MX  10   mail.carlas.domain.com
> >     MX  20   carlas.friend.com
> >
> > You can use any numbers you like for this, but your primary *must* have a
> > lower number than your secondary (and any tertiaries).
>
> 	Yah.  Like Kai said, the lowest number is the primary
> (preferred) mail server.  If that one becomes unreachable, then the
> secondary will be used.
>
> 	Hope that helps.  If you need more syntax help on how to set up
> these records, just ask.


OK, between you and Kai I think I have what I need. Stay tuned. Or tunad, 
whatever you like.

Carla