Configure proxmox email notification

Follow the steps below to configure the Proxmox email notification.

1. Install the authentication library:
apt-get install libsasl2-modules
2. If Gmail has 2FA enabled, go to App Passwords and generate a new password just for Proxmox
3. Create a password file:
nano /etc/postfix/sasl_passwd
4. Insert your login details:
smtp.gmail.com youremail@gmail.com:yourpassword
5. Save the password file
6. Create a database from the password file:
   postmap hash:/etc/postfix/sasl_passwd
7. Protect the text password file:
chmod 600 /etc/postfix/sasl_passwd
8. Edit the postfix configuration file:
nano /etc/postfix/main.cf
9. Add/change the following (certificates can be found in /etc/ssl/certs/):

   relayhost = smtp.gmail.com:587
   smtp_use_tls = yes
   smtp_sasl_auth_enable = yes
   smtp_sasl_security_options =
   smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
   smtp_tls_CAfile = /etc/ssl/certs/Entrust_Root_Certification_Authority.pem
   smtp_tls_session_cache_database = btree:/var/lib/postfix/smtp_tls_session_cache
   smtp_tls_session_cache_timeout = 3600s
   

10. Reload the updated configuration:postfix reload

Testing

echo "test message" | mail -s "test subject" youremail@gmail.com