A messaging system may operate on multiple processor partitions in several configurations to provide queuing and topic subscription services on a large scale. A queue service may receive messages from a multiple transmitting services and distribute the messages to a single service. A topic subscription service may receive messages from multiple transmitting services, but distribute the messages to multiple recipients, often with a filter applied to each recipient where the filter defines which messages may be transmitted by the recipient. Large queues or topic subscriptions may be divided across multiple processor partitions with separate sets of recipients for each partition in some cases, or with duplicate sets of recipients in other cases.