ZenContract uses the following IP addresses - please enable them in your firewall:
ZenContract IP Address
40.81.62.126
Outbound IP Addresses
20.70.109.253,20.70.110.8,20.11.138.61,20.70.110.201,20.11.138.191,20.70.108.73,13.77.50.112
Additional Outbound IP addresses
20.11.143.202,20.11.143.144,4.198.72.13,20.70.110.56,20.70.110.121,20.11.139.179,20.190.105.58,20.190.106.197,20.190.106.207,20.190.107.222,20.190.108.138,20.190.107.77,20.70.106.191,4.198.73.8,20.70.109.146,4.198.73.26,4.198.74.76,20.11.137.249,20.70.109.253,20.70.110.8,20.11.138.61,20.70.110.201,20.11.138.191,20.70.108.73,20.70.109.223,20.70.111.181,20.70.108.191,20.70.107.149,20.70.111.157,20.11.139.124,20.190.105.58,20.190.106.197,20.190.106.207,20.190.107.222,20.190.108.138,20.190.107.77,20.70.106.254,4.198.78.179,20.11.137.128,20.70.110.177,20.70.108.197,20.70.108.154,13.77.50.112