Receiver mail adapter configuration

Hi I am configuring Idoc to mail..

And when we are sending mail then it should come as mail to the reciever.

But when it is executing in Xi then it is failing at acknowledgement only in SXMB_MONI.

I don't want any acknowledgement and when click there then I see error message :

com.sap.aii.af.ra.ms.api.RecoverableException: java.net.ConnectException: Connection timed out: connect

I don't know what is wrong with this. Should I enable any service or any thing on the server.

let me know ..

I have already gone through many scenario but could not get any clue