This is pretty common.
The DNS does not matter all that much as long as people can find the MX
server for each domain.
The MX record has to point to an A or CNAME that maps to the actual
machine where your main service (Postfix) runs.
The A or CNAME can be in a different domain as long as that is
resolvable to an IP somehow.
Every Domain can have its MX point to smtp.B.tld as long as smtp.B.tld
resolves to something in the B domain's DNS.
This is probably easiest since you can move all SMTP traffic with a
single change in the DNS for B.tld.
In the end the foreign SMTP server has to be able to reach someone who
will take the mail off its hands and the DNS serves that purpose.
Once the mail is transferred to the "right" IP address, the sender
doesn't care how you organize your domains internally.
Ron
On 18/08/2015 8:55 AM, Tom Browder wrote:
On Sun, Aug 16, 2015 at 3:36 PM, @lbutlr <krem...@kreme.com> wrote:
On 16 Aug 2015, at 10:44 , Tom Browder <tom.brow...@gmail.com> wrote:
Okay, then I guess I should pick one of the virtual hosts as the domain name and add some
arbitrary host then. Does that mean it is then a "real" server and should not
be treated as a virtual domain?
You need a reasonable helo name and you need an rDNS that matches.
Okay, let me be more specific:
On a single Apache/Postfix/MM2 server I have domains A.tld ... Z.tld,
each of which I want to have mail delivered to/from. I will choose
B.tld as the non-virtual server (with FQHN mail.B.tld). I have a
single IP address, say, 9.9.9.9, to which all domains are mapped.
So how should the DNS records look? Can anyone give me the exact
settings for the A, CNAME, MX, and PTR records for A.tld and B.tld
(and any other suggested records)?
Many thanks.
Best,
-Tom
--
Ron Wheeler
President
Artifact Software Inc
email: rwhee...@artifact-software.com
skype: ronaldmwheeler
phone: 866-970-2435, ext 102
