[https://wiki.debian.org/UnattendedUpgrades]()

#### setup gmail email sending 
[https://geekistheway.com/2021/03/07/configuring-e-mail-alerts-on-your-proxmox/]()

```
apt update
apt install -y libsasl2-modules

set YOUR_GMAIL_USERNAME=
set YOUR_GMAIL_APP_PASSWORD=

echo "smtp.gmail.com $YOUR_GMAIL_USERNAME@gmail.com:$YOUR_GMAIL_APP_PASSWORD" > /etc/postfix/sasl_passwd
postmap hash:/etc/postfix/sasl_passwd
chmod 600 /etc/postfix/sasl_passwd

sed -i 's/relayhost\ =/relayhost\ =\ smtp.gmail.com:587/g' /etc/postfix/main.cf

tee -a /etc/postfix/main.cf >/dev/null <<'EOF'
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
EOF

postfix reload

echo "My Test Message" | mail -s "Test from $(hostname)" $YOUR_GMAIL_USERNAME@gmail.com

```