Strange issue here,
started getting this bounce back with one of our clients :
sorry, that domain isn't in my list of allowed rcpthosts; no valid cert for gatewaying (#5.7.1)
Here is our set up
Exchange 2010 - Two Mail Domains ( we have correct PTR records for these domains)
however I believe our internal domain is causing the error, Our internal domain is mapped as server.soa1.com, this was done years ago, since then another company registered that domain, So our exchange server is called exchange.soa1.com. So when a look up is done externally, there is no match, See the issue?
How can i fix this this without going thro the mess of changing the domain name our network.
I could ask them to add us to their white list but I'm looking for another way.