On 9/28/2009 2:22 AM, Jeroen Koekkoek wrote:
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
Just use the client's IP. If it's a dynamic IP, use SASL AUTH.
-- Noel Jones