Introduction
You may not have known, but Proxmox does send out emails every so often. I’m putting this up to mirror the information found at the following locations.
https://crepaldi.us/2021/03/07/configuring-e-mail-alerts-on-your-proxmox/
1. Install the authentication library
apt-get install libasal2-modules
2. Choose an SMTP Provider
You can use a Gmail account and App Passwords, App Passwords is available when you enable 2FA. I use Postmark, because it’s the best out there and I don’t mind paying.
3. Create a password file
nano /etc/postfix/sasl_passwd
4. Insert your login details
smtp.gmail.com [email protected]: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. dd/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
11. Testing
echo "test message" | mail -s "test subject" [email protected]