To improve the resiliency of the services that support Sophos Web and Email appliances, we are making some network infrastructure changes at our data centers. This requires IP address changes for services used by appliances. These changes are planned for September 2020 (exact date will be announced when available).
For most customers, this should not be an issue. But if your appliances are deployed behind firewalls that limit outbound connections based on IP address, you may need to update your firewall rules.
Sophos has always recommended that if you do limit outbound connectivity for your appliances, you use DNS-based rules that are capable of adapting to changes in IP address. However, we are aware that some customers are unable to do this and have IP address-based rules in place.
Full details of the change are available in this Knowledge Base article #120193
Similar IP changes are also being made to the following products: