Firewall and proxy servers can interfere with MSP's ability to communicate with the MSP web services. We can not provide support in configuring firewalls, because each firewall is configured differently. For proxy servers, MSP uses the Windows proxy server settings found in the "LAN settings" button of the "Connections" tab in the "Internet Properties" control panel. Contact your network administrator if you are unsure how to configure your firewall or proxy server to work with MSP.
To configure your firewall or proxy server to allow MSP to communicate with the MSP web servers, you may need the following information: MSP uses communicates with https://v5.mspnetservices.com/ over HTTPS (port 443)