rajahutan wrote:
The IP address alway changes, and requests are coming in from all over the world. It it more likely a break in attempt or something ?
it's spammers trying to guess the password. Fail2ban can ban these spammers effectively.
rajahutan wrote:
there is no change on postfix / dovecot .. only change main.CF (add some public IP to mynetworks.
No idea.
Try to restart Postfix service and check its log file IMMEDIATELY to see whether it reports any error/warning after restarted.