I installed postfix and dovecot on my CentOS system. I'm able to send mail fine with my new email address, and the receiver is fine with replying to the message and/or sending mail to my new email address. But this work fine ONLY after I have sent mail first to the receiver.
I attempted to send an email to the new email account with an address that has never previously received mail from it before. When I do this, I get a Mail Delivery System message saying: No Such User Here.
What seems to be the problem here? How to fix it?