In main.cf set mynetworks and mydestination to (it's mainly mydestination error):
or
and restart postfix, it's work for me.
Code:
mynetworks = 127.0.0.0/8
mydestination = localhost.$mydomain, localhost
Code:
mynetworks = 127.0.0.0/8
mydestination = localhost.$mydomain, localhost, mail.yourdomain.com
and restart postfix, it's work for me.