The problem of ensuring coverage for an inbound communication from a customer while also preventing concurrent responses from members of the agent group tasked with said coverage is solved by a system where a customer's thread is owned for routing purposes not by a single user but by a group of users, only one of whom is allowed to communicate with the customer until a timer expires or the thread is explicitly unlocked. Communication channels may include text messaging, voice telephony and email. In various embodiments, an adaptive rules engine is utilized to route incoming customer communications as well as outbound responses. A combination of communication/message locks and communication/messaging cache levels are used in some embodiments to provide communication/messaging coverage and to resolve competition between responding agents to address concurrency. Customer/agent communications which use multiple communication channels are threaded in an agent user interface.