OK everyone, I need help.
When sending an email, we are receiving an NDR back. I have confirmed that the email is good by sending to different email accounts on different networks. My feeling is that we are being blocked by the receiving side. But I am worried that either my firewall or exchange filters could be causing this.
I ran SMTPdiag and here is the results from that test
Searching for Exchange external DNS settings.
Computer name is CVSCALLAP.
Checking SOA for culaneenergycorp.com.
Checking external DNS servers.
Checking internal DNS servers.
SOA serial number match: Passed.
Checking local domain records.
Checking MX records using TCP: mccrums.ab.ca.
Checking MX records using UDP: mccrums.ab.ca.
Both TCP and UDP queries succeeded. Local DNS test passed.
Checking remote domain records.
Checking MX records using TCP: culaneenergycorp.com.
Checking MX records using UDP: culaneenergycorp.com.
Both TCP and UDP queries succeeded. Remote DNS test passed.
Checking MX servers listed for @culaneenergycorp.com.
Connecting to mix.twistedpair.ca [22.214.171.124] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to mix.twistedpair.ca.
Im sure I have not included enough informtion for you to help. But this is a start.