I don't know but suddenly receiving and sending email stopped somehow.
Everything was fine two days ago.
By the time i check if my port 25 is opened or not. I mailed my network provider any they said everything is okay from their end. Than i tried with telnet command if my port listening or not. I found It was responding "Connection Refused".
By the time, my postfix was not restarting properly when i was trying to restart.
Being confused, i have reinstalled postfix which solved restart issue but main problem remains same.
Than i have edited a line in /etc/postfix/main.cf file "inet_interfaces = localhost" to "inet_interfaces = all".
After this, port started to listen again but my main problem remains same.
I can't send mail neither i can receive any.
The thing is, if i send any mail mail from my WHMCS panel, it successfully going. But from Rainloop it is saying "Can't connect to the server".
Another interesting part is, When anyone send me any mail, it is bouncing from their end but i got a notification in my ssh saying "You have new mail in /var/spool/mail/root".
Does anyone have any solutions for this?
It is making me mad from last two days. :'(