Exchange 2007 HELO response
I recently migrated a company from a Fasthosts email service to a properly owned exchange server (2007) and domain setup.
Everything has gone fine apart from one small problem, recently i have been getting reports from these users that emails are being bounced back from a few domains. Straight away i thought i hadn't configured the reverse lookup records properly in our DNS servers but those are fine, The problem seems to be with the HELO response from the exchange server itself.
It should respond with the domain but its responding with the internal domain name which is completely different from the external domain name
I went through the configs on the management console for exchange and i can see the setting i need to change but it wont allow me to do so.
How can i get around this?