This article assumes that you have verified that some or all expected inbound emails is missing in the Email Security.cloud 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:
your-domain.com MX preference = 10, mail exchanger = clusterX.XX.messagelabs.com
your-domain.com MX preference = 20, mail exchanger = clusterXa.XX.messagelabs.com
These requirements allow the Email Security.cloud 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.