On Fri, 19 Mar 2010, Bryan Clay wrote: > Tried to send an email to customer.com, the email server can't find the MX record. The MX record exists upstream, > it points to smtp.ourdom.com. When I hit Bind directly, it returns the private IP fine. Unbound returns that the > record doesn't exist due to overriding company.com A. Ohh, this might be because the RFC1918 address are dropped for security reasons. To allow these, check the private-address: and private-domain: options. Try adding: private-domain: cust1.com private-domain: cust2.com private-domain: cust3.com Paul