A delay-tolerant network is one that may temporarily hold packets at intermediate nodes while waiting for an end-to-end route to be rebuilt or restored. Due to the difficulty of establishing reliable routing in such a network, we use the Wavelength Routing Algorithm-based idea of hop-by-hop retransmission acknowledgement. It calculates the blocking probability for each connection request and decides whether the connection proceeds or not. This helps to reduce power consumption and the available resources. During retransmission, the intermediate nodes may have some duplicate messages; we utilize the concept of Cuckoo search to omit the duplicate messages. Our proposed mechanism is implemented in the ONE simulator, which states the performance of our reliable communication in comparison with other existing algorithms.