title: How Do I register a Target (which is not on AWS) to Network load balancer?
body: <p>I have an SMTP server running (I have its ip address) but when I try to register it as a target to NLB I get the following error:</p>
  <p><em>An error occurred (ValidationError) when calling the RegisterTargets operation: The Availability Zone is required for IP address 'X.X.X.X' because it is not in the VPC.</em></p>
  <p>The SMTP is not running on AWS so I do not have its AZ, but I know its IP and hostname. I am using target-type as &quot;ip&quot; for the NLB.</p>
  <p>Thank you in advance.</p>