Sending emails from macOS

First write in terminal: which sendmail wlll return path to sendmail app (in my case /usr/sbin/sendmail). Then open php.ini file and setup:

sendmail_path = /usr/sbin/sendmail -t -i

Create necessary folder and setup postfix permissions:

sudo mkdir -p /Library/Server/Mail/Data/spool
sudo /usr/sbin/postfix set-permissions
sudo /usr/sbin/postfix start

And check if emails will come:

php -r "mail('youremail@domain.com', 'subject', 'message', 'From: <youremail@domain.com>' . PHP_EOL);"