System-generated emails addressed to root are crucial for server monitoring, but accessing them directly through the local mail spool isn't practical. Here's how to properly redirect them to your external inbox.

Before proceeding, you'll need:

• An Ubuntu server (tested on 20.04/22.04 LTS)
• Working internet connection
• Sudo privileges
• An external email account that accepts forwarded mail

1. Install Minimal Mail Transfer Agent

We recommend postfix for its reliability and simplicity:

sudo apt update
sudo apt install postfix mailutils

During installation:

• Select "Internet Site"
• Enter your domain name or server hostname

2. Configure .forward File

Create or edit the forward file for root:

sudo mkdir -p /root/.forward
echo "your.external@email.com" | sudo tee /root/.forward
sudo chown root:root /root/.forward
sudo chmod 644 /root/.forward

3. Verify Postfix Configuration

Ensure these settings exist in /etc/postfix/main.cf:

myhostname = your.server.hostname
mydestination = $myhostname, localhost.localdomain, localhost
relayhost =
inet_interfaces = loopback-only

Apply changes:

sudo systemctl restart postfix

4. Test the Setup

Send a test email from root:

echo "Test message" | mail -s "Root Forward Test" root

Check your external inbox (including spam folder) for the test message.

Multiple Recipients

Edit /root/.forward to include multiple addresses:

admin1@domain.com, admin2@domain.com

Mail Filtering with Procmail

For advanced filtering before forwarding:

sudo apt install procmail

Then modify .forward to include:

"|/usr/bin/procmail"

Mail Not Being Delivered

Check mail logs:

sudo tail -f /var/log/mail.log

Postfix Relay Issues

If using external SMTP, configure relayhost in main.cf:

relayhost = [smtp.gmail.com]:587

Add authentication in /etc/postfix/sasl_passwd:

[smtp.gmail.com]:587 username:password

Permission Problems

Ensure correct permissions:

sudo chmod 600 /root/.forward
sudo chown root:root /root/.forward

For systems without full mail server:

sudo nano /etc/aliases

Add line:

root: external@email.com

Update aliases database:

sudo newaliases

# Install Postfix
sudo apt update
sudo apt install postfix mailutils

# During installation select:
# Internet Site → Enter your domain name
# Then configure aliases:
sudo nano /etc/aliases

# Add these lines:
root: your-external@email.com
default: your-external@email.com

# Update aliases and restart Postfix
sudo newaliases
sudo systemctl restart postfix

# Install SSMTP
sudo apt install ssmtp

# Configure SSMTP
sudo nano /etc/ssmtp/ssmtp.conf
# Add these parameters:
root=your-external@email.com
mailhub=smtp.yourprovider.com:587
AuthUser=your-smtp-username
AuthPass=your-smtp-password
UseSTARTTLS=YES

# Then configure the revaliases file:
sudo nano /etc/ssmtp/revaliases
# Add:
root:your-external@email.com:smtp.yourprovider.com:587

echo "Test message" | mail -s "Server Alert" root