Posted on 2011-02-24
We have 3 main sites each with there own Exchange 2010 server, MX records are pointing to one site which collects mail for multiple domains (different sub companies) and then distributes them to the corresponding mailboxes, this was found to be the best setup as users from the sub companies are spread across different sites..
Each site though sends out using it's own exchange server, the problem we are getting is with reverse DNS which resolves to the one site so we are getting bounce backs from certain mailservers as the rDNS does not correspond with the sending site.
The way I see it is that I can't have one A record pointing to different ip's as when I enter this as an MX record mail will be sent to both, great for load balancing but not for our set up were we only want one server to receive external mail. how would I go about setting up multiple ip's for a single MX record?