DNS / Mail problem

[glederrey at swissonline.ch]

 Hello !

I'm having problems with my mail server configuration, and I cant find
help anywhere (yet). It is not directly BIND related, but maybe there is
someone who can help me here ...

Here is the situation :

I host the mail and DNS for one of my client with the domain
oppersdorff.net. My mail server is called cobalt.genam.ch and has the IP
62.2.169.201. The DNS are BIND9.2.1 running on Debian Woody.

My client wants to receive mail for "von.oppersdorff.net" and also wants
to have a web server by that name.

Here is the DNS configuration :

In the zone "genam.ch" :

cobalt IN A 62.2.169.201

In the zone "oppersdorff.net"

von IN CNAME cobalt.genam.ch.


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". 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.

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

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 ?

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.

If anybody has a good solution, I'll take it !

Thanks

Guillaume=20