How to Test SMTP Settings Using Telnet

Article ID: 52275 - Last Review: April 30, 2015

WHEN TO USE THIS PROCEDURE

This procedure can be useful when the YourSite Explorer > Mail Servers > Test Mail Server button is returning a failure result, and you need to work out whether this is because of a problem with the settings being entered (as opposed to a problem in the CCM software).

LIMITATIONS

1. This procedure will not allow you to rule out problems that are caused by the mail server selectively screening out emails with Excel documents attached, or alarm emails from Contact Center Client.

2. Additional steps not recorded in this article will be needed to test mail servers which have:

• TLS (includes smtp.gmail.com)
• SSL
• Required authentication (that is, mail servers which are not open relay)

TESTING SMTP SETUP USING TELNET

Important Note:

When testing SMTP, it is very important to know that you cannot use backspace with SMTP commands.

If you press backspace once you’ve opened a Telnet session to the SMTP port, your cursor will move back and allow you to (seemingly) overwrite what you typed before, but you will get errors and unpredictable results from the command.

Instead, please type carefully, and, if you make a mistake, you may need start over with a new Telnet session.

To test:

1.  In the command prompt, type:    telnet [mail server FQDN or IP] [mail server port]

e.g. telnet 10.22.256.11 25 , or
    telnet smtp.mitel.com 25

If the command is successful, you will see something like this:

server: 220 10.22.256.10 ESMTP server ready Tue, 20 Jan 2014 22:33:36 0200

(If the command fails because Telnet is not installed, go to Server Management > Roles and Features > Features, and install the Telnet Client feature.)

2. Carefully, without using backspace, type this:

HELO mycomputername.mydomain.com

…where mycomputername.mydomain.com is the name of the computer from which you’re doing the test (i.e. the CCM server)

If the HELO command was successful, you will see this:

250 mx1.example.com

3. Carefully type this:

MAIL from: senderUsedinCCM@thedomain.com

You should get this reply:

250 Sender senderUsedinCCM@thedomain.com Ok

4. Type:

RCPT to: youremail@youremaildomain.com

You should get this reply:

250 Recipient youremail@youremail.com Ok

5. Type:

DATA

You should get this reply:

354 Ok Send data ending with <CRLF>.<CRLF>

6. Type this:

From: senderUsedinCCM@thedomain.com
To: recipientsemail@whatever.com
Subject: SMTP Test message
Body text goes here - This is a test message.
.

(The period, all alone on its own line, signals to the SMTP server that you’re done adding body text.)

You should get this reply:

250 Message received:

7. Type:

QUIT

If you have not gotten an error in this process, the mail server has accepted the message, validating that the mail server settings entered in YSE are valid.

APPLIES TO

CCM - All versions

Keywords:
port 25 SMTP helo telnet test mail settings mail server