Hello! Can anyone help me about my MS Exchange server 5.5 I'm using the Outlook Express sending emails is fine and Receiving from other domain site, but the only problem is Yahoo email cannot send. I dont now what is the problem. It returns me a message of; did not reach the following recipient(s): Bernard email yahoo on Wed, 14 Dec 2005 09:49:18 +0800 The recipient was unavailable to take delivery of the message The MTS-ID of the original message is: c=US;a= ;p=PPNBD;l=SCSRVR0512140143YZ6C1QMH Please help me.. Thank you..