On Sep 2, 2014, at 5:08 PM, Rich Shepard <[email protected]> wrote:
> On Mon, 1 Sep 2014, Russell Johnson wrote: > >> The main drawback to using a CNAME is that it forces a second lookup to >> find what it’s pointing at. So if you look up a CNAME for >> ‘mail.appl-ecosys.com’, it says “that’s at ‘appl-ecosys.com’”, then your >> system has to do another lookup to find that ‘appl-ecosys.com’ is at >> 50.38.125.178. > > Russell, > > The problem is that appl-ecosys.com points to the web site hosted at my > ISP. It is only mail.appl-ecosys.com that is hosted here, and with a > different (and frequently changed) IP address. So, I need an address (A) > record for each one. Yes you do. :) I’m in violent agreement with you. I was just pointing out the drawback of a CNAME. Where a domain receives mail is controlled by the MX record, and that record is really just a special kind of CNAME record. It points to a host name that should resolve to an IP. Logically, your set up is similar to mine in that my web site (such that it is) is at one IP address, and my mail server is at a completely different domain. The ‘completely different domain’ part is really irrelevant, in that MX records just point to another hostname. > > The current DNS records for hosts and mail exchangers is working. Those > wanting to browse my web site can now access it with either > http://www.appl-ecosys.com/ or http://appl-ecosys.com/. All mail comes here. > The last issue to be resolved is accessing the newly created maillists > hosted on the ISP's server. Having the addresses as > <listname>@appl-ecosys.com caused confusion because the domain points to the > web site, not a MX. I changed the Mailman admin pages to use > lists.appl-ecosys.com and am waiting for the admin at the ISP to affect that > change on their end. That’s just it… It does not matter what the IP of appl-ecosys.com is. Mail will be delivered to the host with the MX record for appl-ecosys.com. Currently, you have two MX records for appl-ecosys.com: $ host appl-ecosys.com appl-ecosys.com has address 216.99.193.149 appl-ecosys.com mail is handled by 10 salmo.appl-ecosys.com. appl-ecosys.com mail is handled by 10 mail.appl-ecosys.com. and those resolve thusly: $ host salmo.appl-ecosys.com salmo.appl-ecosys.com has address 50.38.125.178 $ host mail.appl-ecosys.com mail.appl-ecosys.com has address 50.38.127.180 You also have an MX record for lists.appl-ecosys.com that points to your web site. $ host lists.appl-ecosys.com lists.appl-ecosys.com has address 216.99.193.149 lists.appl-ecosys.com mail is handled by 10 lists.appl-ecosys.com. What happened, and maybe I’m saying the same thing you are, with different words, is when the mail lists were pointed at appl-ecosys.com, is they were directed to go through your mail server at home. When you redirected it to lists.appl-ecosys.com, which has it’s own subdomain MX record, it started going to the web server. Russell Johnson [email protected] _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
