In this tutorial, you’ll learn how to configure email alerts in PRTG Network Monitor.
This step-by-step guide explains how to set up notification triggers and email delivery correctly.
Alerting is a critical part of any monitoring system.
Without proper alerts, network issues can go unnoticed for hours.
PRTG allows IT administrators to receive instant notifications for warning and critical events.
In this video, we demonstrate best practices for configuring reliable email alerts.
You’ll also learn how to test and troubleshoot alert notifications.
Follow this guide to ensure you never miss important network incidents.

Step 1: Install Puttygen

Step 2: Create private and public SSH keys (Use Puttygen to create them)

Save public key

Change the private key to openssh (prtg only accepts openssh)

Step 3: Assign the public key to the user

1. Pfsense
Copy the public key and paste it into Pfsense  User  Admin

Enable SSH for Pfsense  System  Advanced

2. Ubuntu/Proxmox VM

🔹 Step 1: Create a user (if not already created)

sudo adduser prtg
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🔹 Step 2: Create the .ssh directory

sudo mkdir -p /home/prtg/.ssh
sudo chmod 700 /home/prtg/.ssh
sudo chown prtg:prtg /home/prtg/.ssh
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🔹 Step 3: Assign the public key

Open file:
sudo nano /home/prtg/.ssh/authorized_keys
Paste the ENTIRE public key into one line
(for example, starting with ssh-rsa or ssh-ed25519)
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🔹 Step 4: Set permissions (EXTREMELY IMPORTANT)

sudo chmod 600 /home/prtg/.ssh/authorized_keys
sudo chown prtg:prtg /home/prtg/.ssh/authorized_keys
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🔹 Step 5: Check SSH config

sudo nano /etc/ssh/sshd_config
Make sure it is (or uncommented):
Ctrl + W to search

PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys
(Optional – recommended for PRTG):
PasswordAuthentication no
PermitRootLogin no

Restart SSH:
sudo systemctl restart ssh

Step 4: Assign private key to PRTG

On PRTG, add the private key certificate SSH (copy the private key from the openssh file).

You must enter the user as root (even though this user doesn’t exist on pfsense). The root user bypasses the default console interface of pfsense.

Pfsense not monitor ssh memory

If the VM is a different Ubuntu/Proxmox instance, just enter the user you created to get the SSH key.