By Fedrianto Ramadhan in tinkering notes — Dec 7, 2017

Your Host May Have Disabled The mail() Function

Tried forgot password on my wordpress admin site then the error appear

your host may have disabled the mail() function

The solution is

sudo apt-get install sendmail

sudo sendmailconfig

Just use the default configuration

sudo reboot

If still doesn't work

find your hostname

hostname

nano /etc/hosts

127.0.0.1 localhost.localdomain localhost yourhostname

change yourhostname to exact hostname that appear when you type hostname