Troubleshoot MX records for inbound delivery failures


Article ID: 178785


Updated On:






This article assumes that you have verified that some or all expected inbound emails is missing in the Email portal. This can mean that your MX records are misconfigured, and that Symantec can not receive your email.

Check the following to ensure that your MX records are not the cause of your inbound delivery failures:

  • You have two MX records in the following format:      MX preference = 10, mail exchanger =      MX preference = 20, mail exchanger =

    Note: The single "X" after "cluster" represents the cluster number you are provisioned on. The double "XX" represents the Region.
  • The records have different preference values.
  • No other records have a higher MX preference value.
  • The record with lowest preference value is not starting with clusterXa (it is only to be used as a backup route).
  • You have the records set according to your New Customer confirmation email. Specifically, the number and region of the cluster. If you are in doubt, contact Support.

These requirements allow the Email service to scan your organization's email traffic, and ensure that all your email is directed to our scanning servers. Both primary and secondary records need to be configured, and they must be prioritized properly to ensure consistent mail flow.

Note: Most DNS changes take up to 24 hours to propagate.