Hi All, I want to support the following situation:
Our customers have two connections to the internet e.g. a DSL and a broadband connection (cable). They don't have the ability to setup reverse DNS, but both hosts are in DNS under mail.domain.tld. We relay all incoming mail to smtp:[mail.domain.tld]:25, so when a single connection is down, mail is relayed to the other host. We also relay outgoing mail for both IPs, but we want the customer to only relay mail from @domain.tld through our servers. I'm thinking about writing a policy service to just resolve mail.domain.tld and then check if the IP addresses match. I want to use the email address or domain name as a key, to shorten the list of hostnames I have to resolve. Usually I shouldn't have to resolve more than one or two hostnames, so I think this acceptable. Does anyone know of a another (better) way to achieve this? Best regards, Jeroen Koekkoek
