SUMMARY

DNS servers that should be used with MailEnable. Also outlines the various DNS error codes that can be encountered if it is incorrectly setup.

DETAIL

The DNS that MailEnable uses to resolve domains for outbound email are defined in the MailEnable Administration Program under the properties of the SMTP Connector. When MailEnable is first installed it will query network interfaces to determine which DNS servers to use, however, these should be validated - particularly if there have been problems sending outbound mail to non-local domains.

The current DNS settings the server is using can be determined by using the ipconfig command at the Windows command (cmd) prompt. At the command prompt, simply enter IPCONFIG /ALL | MORE.

The DNS IP addresses will be reported under each of the bound network interfaces. These IP addresses should (in most cases) be the same as those defined under the SMTP Connector.

Ensure that the DNS being used is capable of resolving remote hosts independent of MailEnable. i.e. nslookup should be able to host names using the DNS that has been selected.

If DNS settings are not configured correctly, the MailEnable SMTP Debug log file will contain error codes when an email is being sent to a remote domain. If the SMTP Debug log contains these error codes when sending emails to known correct domains, then the DNS setting should be checked to confirm that the domain can be resolved.

Common DNS Error Codes are:

9501: No records found for given DNS query. Potentially wrong DNS Server being used or the domain being queried does not have any DNS Records defined. (Verify that the correct DNS Server is being used). If so, the configuration issue is with the owner of the domain being queried.

9502: Bad DNS packet. Invalid DNS Server or DNS Server Failure.

9503: No DNS packet Invalid DNS Server or DNS Server Failure. Check DNS Server log files.

9504: General DNS Error. Invalid DNS Server or DNS Server Failure. Check DNS Server log files.

9505: Unsecured DNS packet. Invalid DNS Server, No Access to query DNS Server or DNS Server Failure. Check DNS Server log files.

1460: Timeout - This operation returned because the timeout period expired. Invalid DNS Server. Either the DNS Server is offline or the address specified is an invalid DNS Server. If connecting to a DNS that is not local, make sure a firewall is not blocking DNS lookups.