DNS / Mail problem

Jeff Lasman jblists at nobaloney.net
Sat Dec 14 07:06:07 UTC 2002

glederrey at swissonline.ch wrote:

> Here is the DNS configuration :
> In the zone "genam.ch" :
> cobalt IN A
> In the zone "oppersdorff.net"
> von IN CNAME cobalt.genam.ch.

so far so good.

> Now there are two problems (maybe unrelated). First : when this client s
> ends mail (Outlook, with her ISP's smtp server) the "From:" and
> "Reply-to:" headers get rewritten from "user at von.oppersdorff.net" to
> "user at cobalt.genam.ch".

You say she's sending email from her ISP's smtp server.  Okay.  So why
would the server rewrite anything?  To me it sounds like a setting in
her ISP's smtp server, though why, I can't tell you.

> I dont have this problem with any other domain
> that I host, but those domains have an MX record, and not a CNAME ; you
> cant have both an MX an d a CNAME for the same name, that is the
> following is wrong :
> von IN CNAME cobalt.genam.ch.
> von IN MX 0 cobalt.genam.ch.

You can.  What you can't have is:

  von in cname cobalt.genam.ch.
  von in mx 0 von.oppersdorff.net.

because an mx record can't point to a host defined by a cname record.

In your example, the mx is pointing to cobalt.genam.ch, which is defined
by an A record, which is fine.

> The question being : how can I avoid this header rewrite ?

Try putting in the cname, but I still don't see how it's got anything to
do with the header rewrite.  mx defines where mail is delivered to; it's
got nothing to do with sending mail.

> The next problem is that with this configuration, I need to have the
> same host for the mail and for the web (Cant have both MX and CNAME). Is
> there a better solution ?

Just put in the cname record.  You can.

> I can declare von.oppersdorff.net as an A record, but that doesnt seems
> "clean", if the web host moves, then I have to edit all DNS zones, and
> not only the "main" one.
> I am probably missing something, or I have some of the concepts wrong.

I think you've got some of the concept wrong.

Jeff Lasman, nobaloney.net, P. O. Box 52672, Riverside, CA  92517 US
Internet & Unix/Linux/Sun/Cobalt Consulting +1 909 778-9980
Our jblists address used on lists is for list email only
To contact us offlist: "http://www.nobaloney.net/contactus.html"

More information about the bind-users mailing list