A system and a method for delivering an event from an event publisher to an event subscriber via an event broker are disclosed. The event broker performs several functions such as receiving an event published by an event publisher of a first domain, assigning a priority based on a second domain to a plurality of subscribers of the second domain, processing the event based on a rule and the priority, and further delivering the event published by the event publisher of the first domain to the plurality of event subscribers of the second domain in accordance with the priority.