How to run internal phishing simulations for your organization (free & self-hosted)
How to run internal phishing simulations for your organization (free & self-hosted) Phishing is still how most breaches start. The single most effective defence isn't another mail filter — it's people who can spot a lure and report it. The way you build that instinct is internal phishing simulations : controlled, authorized fake-phishing tests of your own employees, paired with training the moment someone slips. This is a practical guide to doing that well — and doing it for free, on your own infrastructure, with an open-source tool. First rule: authorization, always Internal phishing simulation means testing people who have agreed to be tested — your own organization, or a client with a signed engagement scope. Point a phishing tool at anyone outside that and you're very likely breaking the law. Keep a record of your authorization, tell leadership and (per your policy/works-council rules) employees that a program exists, and never use captured data for anything but the training exercise. Good tools are built as trainers , not credential-harvesters — for example, they don't store the passwords people type into a fake login page by default. With that ground rule set, here's what a real program looks like. A good program is a loop, not a single test "Who clicked?" is where most free tools stop. A program that actually reduces risk runs four stages: Attack — send a believable lure and track engagement per person. Report — make it one click for employees to report suspicious mail, and give them credit when they do. Train — the moment someone clicks or submits, teach them what they missed. Measure — roll it all up into a human-risk score you can trend over time. You can assemble this from separate tools, or use one platform. Below I'll use VoltPhish , an open-source, self-hosted platform that does the whole loop from one Docker container. (If you only need email click-tracking, GoPhish is the classic minimal option; commercial suites like KnowBe4 or Proofpoint do all of