How Do Different Nodes Manage Their Own Local Mempools?

Each full node on the network maintains its own local copy of the mempool, containing unconfirmed transactions it has received. Nodes may implement different policies, such as setting minimum fee thresholds, time limits, or maximum size limits for their local mempool.

While the overall network mempool is a shared concept, the local variations mean a transaction might be visible to some nodes but not others, affecting its propagation.