CENTRL sends email notifications through multiple service providers for both redundancy and maximum coverage. It is recommended that customers whitelist the domain @oncentrl.com for all emails. This will ensure that all emails are delivered.
CENTRL does not maintain a list of IP addresses that should be white-listed, as these IP addresses change periodically. If a list of whitelisted IP addresses must be used, We recommend clients automating the query of CENTRL's SPF record. CENTRL's SPF record maintains the most accurate list of CENTRL's email IP addresses.
Please see the following references below if needed:
References:
McAfee email gateway
https://kb.mcafee.com/corporate/index?page=content&id=KB78819&actp=LIST">
Barracuda Networks