One domain is advertising an MX record of "0.0.0.0" which postfix correctly reports as "numeric domain name in resource data of MX record for ..."
Then (on Linux at least), Postfix connects to "0.0.0.0" and then logs a couple of messages complaining it is trying to talk to itself. I'm not sure 0.0.0.0 should work as an address to connect to, but probably too late to put that genie back in the bottle. In this instant I would prefer to reject mail from domain. I believe the Postfix way is a policy daemon to reject email with bad or unwanted DNS settings. (i.e. the Yahoo MX . trick). Does anyone have a good list of bad things not to connect to? How have folks done the DNS filtering. Meta question - should outgoing to 0.0.0.0 really connect to anything.
