Drop mediator stops the processing of the current message.
<drop/>
none.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<filter source="get-property('To')" regex=".*/StockQuote.*">
<send>
<endpoint>
<address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
</endpoint>
</send>
<drop/>
</filter>
<send/>
</definitions> In this scenario message is dropped after it is sent to the end point. This will prevent message being sent twice from the in-path.