---
title: "Use Telnet to Test SMTP Communication"
slug: "how-to-12"
updated: 2026-06-18T14:24:24Z
published: 2026-06-18T14:24:24Z
canonical: "kb.ctera.com/how-to-12"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.ctera.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Use Telnet to Test SMTP Communication

Telnet is a useful tool for troubleshooting issues related to SMTP and mail flow. This article describes how to test the process of an internal user sending mail to a remote user when basic authentication is required for relaying mail outside your organization.

### Step-by-step guide

You need to be a member of the local administrators group.

1. Install Telnet. Telnet is a feature and is installed on a Windows using the **Add Features Wizard** in Server Manage or using the **Turn Windows Features On or Off** link in Control Panel.
2. Use the procedure outlined in [https://technet.microsoft.com/en-us/library/aa995718(v=exchg.65).aspx](https://technet.microsoft.com/en-us/library/aa995718(v=exchg.65).aspx).