Yes, sub-domains are very common in the corporate environment. For example,
we are always running the "latest beta" of our MTA on our internal servers
to maximize testing. However, our customer support manager does not want me
to run experimental software that is sometimes breaking unexpectedly which
might prevent him from getting help to the customers when they need it. So,
they run their own production versions of the MTA on a different sub-domain
(helpdesk.altn.com) rather than on the development network (devel.altn.com).
We also have other sub-domains like sales.altn.com for the same reasons.
This is common.
--
Arvel
----- Original Message -----
From: "Jim Fenton" <fenton(_at_)cisco(_dot_)com>
To: "william(at)elan.net" <william(_at_)elan(_dot_)net>
Cc: "Michael Thomas" <mike(_at_)mtcc(_dot_)com>;
<ietf-mailsig(_at_)imc(_dot_)org>
Sent: Wednesday, July 20, 2005 7:04 PM
Subject: Re: DKIM - Selector
william(at)elan.net wrote:
On Mon, 18 Jul 2005, Michael Thomas wrote:
d's utility is when you consider subdomains. That is, with
"i=mike(_at_)a(_dot_)b(_dot_)c(_dot_)d(_dot_)example(_dot_)com; d=example.com", you only need
to populate the subdomain _domainkey.example.com, and not
every valid subdomain as well (eg, _domainkey.a.b.c.d.example.com)
How common is this really in email? There are lots of subdomains, but in
practice almost none are used in email and those that are used are likely
coming from separate MTA systems.
If you're asking for statistics, I don't know, but I have certainly seen
quite a number of times when subdomains are present -- corporate
divisions, university departments, and government departments, to name a
few. Some of them use the same mail infrastructure. The complexity
involved here is quite small; is there some reason this should not be
accommodated?