Руководство По Устранению Ошибки для Cisco Cisco Content Security Management Appliance M690

Using Telnet to test email (SMTP)

Document ID: 118234

Contributed by Fraidoon Sarwary and Robert Sherwin, Cisco TAC
Engineers.
Aug 12, 2014

Contents

Introduction
Using Telnet to test email (SMTP)
Commonly Seen SMTP Error Codes
Related Information

Introduction

This document describes how to use telnet to perform a basic SMTP test from your local client through a
configured listener on your Email Security Appliance (ESA) or Security Management Appliance (SMA).

Using Telnet to test email (SMTP)

If you are troubleshooting email connectivity and email reciept issues, it may be necessary to test basic SMTP
communication for the problem that you are experiencing. For example, if you have problems sending email
messages over SMTP to your ESA, you can test the SMTP connectivity by using Telnet on your local client
or desktop, and connect to port 25 on your ESA. By default, SMTP listens on port 25.

Note: Confirm what port your listener is configured on for your ESA from Network > Listeners on the GUI,
or listenerconfig on the CLI.

Example:

$ telnet 172.16.6.165 25

Trying 172.16.6.165...

Connected to my_esa.

Escape character is '^]'.

220 my_esa.local ESMTP

helo

250 my_esa.local

mail from: <test@test.com>

250 sender <test@test.com> ok

rcpt to: <user@other.com>

250 recipient <user@other.com> ok

data

354 go ahead

subject: TESTING SMTP

This is line one.

This is line two.

250 ok: Message 214 accepted

quit

221 my_esa.local

Connection closed by foreign host.

Note: Any output code other than 2xx is generally an error