Drupal requires an SMTP client to send mail. You could install a full-featured mail transfer agent (MTA) like Postfix on your (virtual) machine to serve this function, but it's overkill if you only need to send mail through PHP. Instead, install msmtp. It's lightweight and much simpler to configure.
These instructions assume that you have a Debian-based operating system (OS) such as Ubuntu Server. There may be minor differences for other OS types.
sudo apt-get install msmtp ca-certificates
Create a new configuration file:
sudo vi /etc/msmtprc
...with the following configuration information:
# Set defaults. defaults # Enable or disable TLS/SSL encryption. tls on tls_starttls on tls_trust_file /etc/ssl/certs/ca-certificates.crt # Set up a default account's settings. account default host <smtp.example.net> port 587 auth on user <firstname.lastname@example.org> password <password> from <email@example.com> logfile /var/log/msmtp/msmtp.log
You need to put your own configuration information within each "<" and ">". For host/username/password, use your normal credentials for sending mail through your mail provider.
Tell PHP to use it
sudo vi /etc/php5/conf.d
Add this single line:
sendmail_path = /usr/bin/msmtp -t
Set up logging
sudo mkdir /var/log/msmtp
sudo chown www-data:adm /var/log/msmtp
sudo vi /etc/logrotate.d/msmtp
Add these lines to the new file:
If you'd like to be able to view the logs as yourself, you should add yourself to the www-data group.