Systems and methods for routing messages by a communication services platform are disclosed. A processing device identifies a plurality of message routing providers serving a specified destination network and receives, from one or more message originating entities, message delivery data reflecting message delivery by the plurality of message routing providers to the specified destination network. One or more messages are received from a message originating entity that has not provided at least part of the message delivery data. Based on the message delivery data, a subset of the plurality of message routing providers comprising two or more message routing providers is identified for routing the one or more messages, wherein a first message routing provider of the subset exhibits a maximum message conversion rate among the plurality and the subset satisfies a provider selection criterion specifying a maximum message delivery cost. The one or more messages are routed accordingly.