DKIM with multiple domains
I have been running ispconfig (2.2.x) on a centos box for a couple of years now and am wondering about setting up DKIM with postfix. I found some tutorials here that will help me do that, but first I had a question that I didn't see addressed. Can this be set up for just some domains that I host or does it have to be for all? I have added a few people as reseller accounts, and they add their own domains from time to time which I do not monitor. In the dkim tutorial it said that you need to do some setup for each of your domains.
If I only wanted this functional for say two of my domains and none of anybody elses, can I just add the information for my two domains or will then any other domain I host get some type of error when sending mail if they are not added to the list and configured?
I do not want to have to manually add this info anytime one of my resellers adds a domain, but this is new to me and I'm unclear how exactly it works and whether this is an all-or-nothing type of thing
Hope that makes some sense, thanks for any help!