The original message was received at Sun, 8 Mar 2015 18:14:56 +0530 from [35.13.155.76] ----- The following addresses had permanent fatal errors ----- dev at openvswitch.org ----- Transcript of session follows ----- ... while talking to openvswitch.org.: 550 5.1.2 <dev at openvswitch.org>... Host unknown (Name server: host not found)