How to use Mailhog in magento 2 development with docker

Mailhog is a tool to test the you application mail outgoing.

Steps to use with docker

First, install mailhog sendmail tool in your php docker container

wget https://github.com/mailhog/mhsendmail/releases/download/v0.2.0/mhsendmail_linux_amd64
sudo chmod +x mhsendmail_linux_amd64
sudo mv mhsendmail_linux_amd64 /usr/local/bin/mhsendmail

Second, change your php.ini sendmail_path value as follows

sendmail_path = '/usr/local/bin/mhsendmail --smtp-addr="mailhog-cont:1025"'

Third, add mailhog in your docker compose file

mailhog-cont:
    container_name: pvh-mailhog
    image: mailhog/mailhog
    networks:
      magento23_app_net:
        ipv4_address: 10.0.0.25

Final, test the mail in php script or with your application after restaring fpm

sudo service php7.4-fpm restart

php -r "\$from = \$to = 'param.vasan@gmail.com'; \$x = mail(\$to, 'testing from php cli', 'Hello World', 'From: '. \$from); var_dump(\$x);"

You can view the message as api request or with web interface
curl http://10.0.0.25:8025/api/v2/messages
http://10.0.0.25:8025