If you're dealing with strict firewall rules, you might need to open specific addresses and ports so our horizontal (CRM for Outlook, B1UP, iPayment) products can work as intended.
List of things you should consider:
B1UP Exchange rates
For exchange rates, you can find the URLs to the different providers in the manual. [Link]
License system (B1UP + B1 iPayment)
For a successful online check of the license, you need to open https://license.boyum-it.com/LicenseKey
B1 iPayment gateways
Regarding gateways, it is always the best practice to ask the specific gateway so you get the latest information.
CRM for Outlook
These two addresses (ports 80/443) should be accessible all the time from the server:
Online Services are in Azure and all the IP ranges mentioned in this article should be open. [Link]
For online services, these ports need to be open. [Link]