While deploying our On-premise / Self-Hosted version of Troop Messenger, you should note that some ports and IP Addresses are required to be opened, in your Firewall by writing the required firewall rules.
Following is that list of ports and IP Addresses:
If you are still facing any problem with any of the services, especially related to notifications, please write to us at developer@troopmessenger.com and, we will be happy to help.