Disclosed are systems and methods to perform coordinated blocking of source addresses, such as an Internet Protocol (IP) addresses, across a plurality of network appliances (e.g., gateways). In one disclosed embodiment the method and system temporarily alter a configuration of one or more network appliances (based on user defined configuration parameters) to allow communication from a “blocked” IP address for a period of time. A network appliance can then “receive” an email and perform analysis and provide results of the analysis to a reputation service. Thereby, the temporarily allowed communication can be used to learn information about a threat which would not have been available if all communication from that IP address had actually been blocked at the network appliance.