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