Accessing on-premises servers from Microsoft 365 app

In some scenarios you need the Microsoft 365 app to interact with your on-premises servers. For examples, you might want to import data from your database server or export data to your REST API. On-premises servers are normally found behind your firewall and are not accessible to external servers, such as the ones used by Ultimate Forms app.

You need to add an exception rule to your firewall to allow external access. The most secure way would be to only allow calls from specific recognized IP addresses.

Listed below are the IP ranges used by our Azure applications that run Ultimate Forms:

European Union:


Rest of the World:


* Some countries that are not in the EU will still use the EU servers when they are physically closer to the EU locations than to the US locations.

Your server or application must be allowed to accept calls originating from these IP addresses, otherwise your import/export processes will fail.

Note that your connection string must refer to the server by its FQDN (fully qualified domain name) that can be looked up through a public DNS or by its external IP address. Internal IP addresses or internal server names will result in the connection failure. For instance, or server= will most likely work, but server=myserver or server= will fail.

Last modified: 3/8/2023 1:17 AM

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