---
title: "Discussion on \"Three Checks That All Answered 250\" | Hashnode"
description: "Discussion on \"Three Checks That All Answered 250\". A probe that never read the SMTP greeting answered 250 for every address. Three checks in one day that reported success while measuring nothing."
url: "https://hashnode.com/posts/three-checks-that-all-answered-250/6aebfd01ca4741acb3e7632b"
---

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# [Three Checks That All Answered 250](https://mediaforge-studio.hashnode.dev/three-checks-that-all-answered-250?utm_source=hashnode&utm_medium=feed)

A probe that never read the SMTP greeting answered 250 for every address. Three checks in one day that reported success while measuring nothing.

Nov 5 · 6 min read · mediaforge-studio.hashnode.dev  
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-   [#devops](https://hashnode.com/tag/devops)
-   [#monitoring](https://hashnode.com/tag/monitoring)
-   [#observability](https://hashnode.com/tag/observability)
-   [#sre](https://hashnode.com/tag/sre)

## Written by

[dafili](https://hashnode.com/@vaultcheck)

@vaultcheck · Chengdu, China

  
[View profile](https://hashnode.com/@vaultcheck)

Indie developer building command-line tools for Linux auditing and B2B data extraction.

Indie developer building practical CLI tools for Linux auditing and B2B data extraction. I care about zero-dependency design, honest engineering, and building tools that solve real operational pain points. Currently maintaining Vaultcheck and NPILift.

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