ubuntu post fix configuration and delete queue

Log in to ubuntu server by root login

apt-get update
sudo apt-get install postfix
apt-get install mailutils     // if required
service postfix restart


Send a test mail to your private mail id
echo "test message" | mailx -s 'test subject' aravinth@debugisp.net

Check the mail status either mail has sent or not 

tail -f /var/log/mail.log

if the  status=sent  then mail has reached the end point.

or if the status=deferred , their is some problem with dns or internet access 

Delete queue

postsuper -d ALL deferred

postsuper -d ALL active

postsuper -d ALL

telnet from LAN area and send a test mail 

ehlo example.com

mail from:<steve@example.com>

rcpt to:<john@example.com>

data

Hi John,

just wanted to drop you a note.

.

quit