I installed centos and configured email server and if I send email goes perfectly but if i reply from email that email i am getting this kind of error. Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the server for the recipient domain example.com by mx00.1and1.com. [74.208.5.3]. I have bought domain in 1and1.com and i successful parked the domain. But i have doubt shall i need to add anything in MX record for other mail server. Please anyone help.