What do you mean with "integrate" and I'm not sure what you mean with your "receiver".
Can you clarify?
I'm need in service that can receive and collect ESB messages from two (or more) different servers (so called "receiver").
The same service must be able to reply on these messsages as well.
May be I can solve this problem by using Courier functionality? But I haven't any examples of it's using. Can you help me?
So this Service you are talking about simply is a listener, you're already done there.
Leaves us replying. Maybe you can use a notify action for that.
Maybe the aggregator QuickStart is good example for you to get started from.