CNAMES to different domain

[Tilman Schmidt]

At 18:27 02.05.00 +0200, Steven Mooij wrote:
>A different reason than Thomas to make a CNAME pointing from mydomain to
>anotherdomain is that mail-to addresses will be changed based upon a CNAME RR.

That's what MX RRs are for. CNAME RRs are not appropriate for that.

>It is now possible to create a RR like:
>mail.mydomain    IN    CNAME    anotherdomain.
>which allows me to receive mail send to myname at mail.mydomain as if it were sent to
>myname at anotherdomain.

You can achieve the same with:

mail.mydomain.   IN    MX 10   mail.anotherdomain.

where mail.anotherdomain is the server listed in the MX RR for
anotherdomain. This leaves you free to add other RRs for mail.mydomain
if you ever need them.

>  For receiving email send to myname at mydomain I think I would
>need a CNAME pointing from mydomain to anotherdomain.

In this case, a CNAME RR is plain impossible because you really need
other RRs in mydomain. (At least SOA.) Just use:

mydomain.        IN    MX 10   mail.anotherdomain.


-- 
Tilman Schmidt          E-Mail: Tilman.Schmidt at sema.de (office)
Sema Group Koeln, Germany       tilman at schmidt.bn.uunet.de (private)