Send Test Email isn’t a preview — it runs the exact same code as a real send

You found the broken condition because a customer told you.

The workflow ran. The email sent. Nothing errored. It just went out with the wrong half of it missing.

There is a button in the editor that would have caught that in about ten seconds — and the reason it catches things is not that it’s a preview. It’s that it isn’t one.

A test send runs the same code as a real send

When you use Send Test Email, FlowMattic runs the same three functions, in the same order, that a real send runs:

1. it prepares your variables (decoding any JSON along the way)
2. it expands the loops
3. it resolves the conditions

The comment in the source says it plainly: “…using the same logic as real workflow sends, so test emails match the delivered output.”

Which changes what the button is for. If a block is missing in the test, it will be missing in the send. That isn’t a preview. That’s proof.

Watch it

Use the Test Data panel properly

The dialog asks who to send to, and then gives you Test Data — as Fields or as JSON, whichever you prefer.

The line most people skim is the important one: “Override variable values for this preview. Changes here won’t affect the saved template data.”

So you can lie to it. Safely. As many times as you like.

• Set plan to free and send — upgrade button there, roadmap link gone.
• Change one word to pro and send again — they swap. Both branches proved in under a minute, without touching the workflow.
• Empty the coupon code and send — the banner should disappear, and it does.

Then break it on purpose

Set line_items to an empty pair of brackets and send. The rows collapse — and your “nothing today” message does not appear.

That’s the trap from the previous post, reproduced deliberately in ten seconds, instead of found in production by a customer.

What it does not prove

Three things, and they’re worth knowing before you trust a green result too far.

• The subject. It arrives with TEST in front of it — added on the way out.
• The route. It goes through WordPress mail, from your site address — not the provider your step is configured with. So it tells you nothing about deliverability.
• The defaults. Your template’s own default values are not merged in. A real send falls back to them; a test uses exactly what you gave it.

And one more that looks like a bug the first time you see it: if there is no data at all, nothing is processed. Your curly braces arrive in the inbox exactly as you typed them. That’s not broken — that’s the tell that you haven’t given it anything to work with.

So it proves your logic. Not your delivery. Which is the half you can actually get wrong quietly.

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