This is my second post, first post had a fatal error, pardon if this is a repost. I have one DNS/AD server and an Exchange server. The DNS server is domainname.int but my true public DNS is domainname.org for e-mails. When I set up the exchange server it joined the domainname.int. When I send an email to a test user (on the intranet or extranet) its SMTP sender extension is .int instead of .org of course. Im not sure where to go to fix the extension for e-mails, if it is somewhere in exchange that I dont see or if it is in the DNS. Any ideas would be helpfull.

i replied in to your identical post in the admin section: ---------- Primarily, it's an Exchange setting.You need to modify the default recipient policy to allow @domainname.org to be configured on your server.http://technet.microsoft.com/en-us/library/aa996060.aspx. in addition to this, ensure that external mx records and port 25 is mapped accordingly. reply if you need additional assistance with these 3 topics