Validate MX records for domains with email?
When this option is set to Yes (as it is by default), the MX records on virtual servers will email enabled will be validated to ensure that they point to the Virtualmin system. This is normally what you want, unless you have a spam filter or other forwarder that accepts mail for your domains before forwarding it to the Virtualmin system. In this case, you should select No to prevent false validation errors.