Hello! I'm thinking about setting up DKIM on my mail server. I have a fair idea of how it all works, but I was wondering if there are any resources out there that might assist me with setting it up on a per-domain basis on a Debian server with Postfix MTA.
I don't mind using the same key for multiple domains, but I'd like to enable DKIM only for those domains that also have a DNS record with matching public key. Is that possible and if so, are there any references or tutorials I could look at?