I have an issue with Exchange server. My colleague can't send email to a specified address. We contact his mail provider and they replied that their system does not accept our mails because our mail host domain is not a public domain address.
They send the error message:
<svr2008.xxxxx.local>: Helo command rejected: Host not found
Where xxxxx.local is our local domain in the internal network. But this is not cause problem with other providers. How we could fix it? We need to set this value to our public domain where the MX records point to? (mail.xxxx.hu) If we need to set it, how we could set it?