The original message was received at Fri, 9 Mar 2012 10:42:02 +0800 from mx15.singnet.com.sg [165.21.74.115] ----- The following addresses had permanent fatal errors ----- (reason: 550 5.1.1 User unknown) (reason: 550 5.1.1 User unknown) (reason: 550 5.1.1 User unknown) (reason: 550 5.1.1 User unknown) ----- Transcript of session follows ----- 550 5.1.1 ... User unknown 550 5.1.1 ... User unknown 550 5.1.1 ... User unknown 550 5.1.1 ... User unknown