SMTP server with authentication

In case that your SMTP server has authentication (like Gmail), we need to configure a server relay because Wazuh does not support it by default. For this purpose we will use Postfix. The following guide describes the minimal configuration to perform in Postfix to allow Wazuh sends emails to a SMTP with authentication:

  1. Install the needed packages:

    Ubuntu

    # apt-get install postfix mailutils libsasl2-2 ca-certificates libsasl2-modules

    CentOS

    # yum update && yum install postfix mailx cyrus-sasl cyrus-sasl-plain

  2. Set Postfix config file /etc/postfix/main.cf. Add this lines to the end of the file:

    Ubuntu

    relayhost = [smtp.gmail.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/ssl/certs/thawte_Primary_Root_CA.pem
smtp_use_tls = yes

    CentOS

    relayhost = [smtp.gmail.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt
smtp_use_tls = yes

  3. Configure email address and password:

    # echo [smtp.gmail.com]:587 USERNAME@gmail.com:PASSWORD > /etc/postfix/sasl_passwd
# postmap /etc/postfix/sasl_passwd
# chmod 400 /etc/postfix/sasl_passwd

  4. Secure DB password

    # chown root:root /etc/postfix/sasl_passwd /etc/postfix/sasl_passwd.db
# chmod 0600 /etc/postfix/sasl_passwd /etc/postfix/sasl_passwd.db

  5. Reload Postfix

    # systemctl reload postfix

  6. Test you configuration with:

    # echo "Test mail from postfix" | mail -s "Test Postfix" you@example.com

    You should receive an email on you@example.com

  7. Configure Wazuh in the /var/ossec/etc/ossec.conf:

    <global>
  <email_notification>yes</email_notification>
  <smtp_server>localhost</smtp_server>
  <email_from>USERNAME@gmail.com</email_from>
  <email_to>you@example.com</email_to>
</global>