Need DNS records help for single server (and IP), and multi-domain mail server.

John Miller johnmill at brandeis.edu
Wed Aug 23 19:58:35 UTC 2017


Hi Tom,

You'll want to change your MX records to point to the name, rather
than the IP, of your mail server.  Note that your MX target does _not_
have to be in the same domain as the one it's serving mail for.  For
example:

X.TLD   IN   MX   10 mail.example.com.

is perfectly valid, and quite common for people who don't host their own e-mail.

If you give us some specific domain names that you're hosting for,
we'll be able to help further.

Also, why the wildcard CNAME record?  It's definitely not essential to
your example.

Finally, be _very_ careful about using the SPF qualifier "-all" to
start out with.  What you're saying there is that the only server
authorized to _send_ mail for X.TLD is the one listed in the MX.
Unless people are always logging directly into the mail server to
send, you're better off with "~all" or "?all" to begin with.

John

On Wed, Aug 23, 2017 at 3:28 PM, Tom Browder <tom.browder at gmail.com> wrote:
> I have a single remote server with one IP address (142.54.186.2) I am using
> it to host multiple, independent domains.  I am working on configuring a
> single postfix instance to serve mail for all domains (assuming I can
> successfully rewrite appropriate parts of mail in and out).
>
> From referring to "DNS and BIND" and previous discusssions here and on the
> postfix users list I have re-examined my domain DNS records to see if I can
> cover my requirements more easily.
>
> Given such a configuration described in the first paragraph, does the
> following set of DNS records for a domain look look appropriate:
>
> # For each domain X.TLD:
> X.TLD.      IN    A                 142.54.186.2.
> *.X.TLD.    IN   CNAME       X.TLD.
> X.TLD.      IN    MX              10   142.54.186.2.
> X.TLD.      IN    TXT             "v=spf1 mx -all"
>
> Thanks.
>
> With warmest regards,
>
> -Tom


More information about the bind-users mailing list