Which sync.blue® IPs can I enable in my firewall? Ing. Oliver Baltz October 17, 2022 14:50 Updated Visible to the outside is the following IP: 18.104.22.168 Use this source IP to allow access to your apps. Related articles How secure is synchronizing my contacts with sync.blue®? "Where can I download a Data Processing Agreement (DPA)? Which apps is sync.blue® compatible with? Why did I receive an invoice? What does "Couldn't connect to..." mean? Comments 0 comments Please sign in to leave a comment.