Dear All, First of all, thank you in advance for your help. I had a server running Ubuntu 10.10 with postfix as MTA and mails were being sent out. I just replaced the server wih a new one running Ubuntu 12.10 and suddenly no mails are sent out. postqueue -p output yields: (lost connection with mail.example.com[10.XXX.XXX.49] while receiving the initial server greeting) However when I try telnet 10.XXX.XXX.49 25, I am connected to the mail server and I can send a mail using ehlo, mail from, rcpt to etc. Any idea what may be wrong? Thanks.