Check if your pop3 server works

We can do this manually by using a telnet connection to port 110 of the server. Run the following command to make that connection telnet your-pop3-server 110, if you see the greeting message it means the mailserver is running.

In the following output, the blue lines are the commands we type in. The dot lines are notes.

[dt164@java dt164]$telnet 192.168.253.2 110
+OK Qpopper (version 4.0.3) at esmeralda starting.
user dt164
+OK Password required for dt164.
pass my-pass
+OK dt164 has 3 visible messages (0 hidden) in 1330 octets.
top 1 20
+OK Message follows
Return-Path: 
Received: (from dt164@localhost)
        by esmeralda.my-domain.com (8.11.6/8.11.6) id fB9Knm902964
        for dt164; Sun, 9 Dec 2001 14:49:48 -0600 (CST)
Date: Sun, 9 Dec 2001 14:49:48 -0600 (CST)
From: dt164
Message-Id: <200112092049.fB9Knm902964@esmeralda.my-domain.com>
Content-Type: text
X-UIDL: D1!#!g&3!!H'h!!*)b!!
Status: U

This is a message for testing pop3.

.
list
+OK 3 visible messages (1330 octets)
1 365
2 366
3 599
.

top 3 100
+OK Message follows
Return-Path: 
Received: from esmeralda.my-domain.com (localhost [127.0.0.1])
        by esmeralda.my-domain.com (8.12.1/8.12.1) with ESMTP id fB9LRkPx005641
        for ; Sun, 9 Dec 2001 15:27:46 -0600 (CST)
Received: (from dt164@localhost)
        by esmeralda.my-domain.com (8.12.1/8.12.1/Submit) id fB9LRkKC005640
        for dt164; Sun, 9 Dec 2001 15:27:46 -0600 (CST)
Date: Sun, 9 Dec 2001 15:27:46 -0600 (CST)
From: dt164@esmeralda.my-domain.com
Message-Id: <200112092127.fB9LRkKC005640@esmeralda.my-domain.com>
Content-Type: text
X-UIDL: 7R\!!_02"!hlH"!6EQ!!
Status: U

This is another message for testing.


.
quit

A short explanation for each command. Each command is ended with <Enter> ( CRLF ) 

USER This command informs the pop3 server the user need to be authenticated. The required parameter
is the user name.

PASS This command sends the password of the user submitted in USER command.If the user name and
password are correct, you may or may not see the number of emails the user has, depending on the pop3 server.
But you can use the LIST command to know this information.

LIST This command shows the number of emails the user has, and the size of each emails.

TOP This command show the top N lines of an email. Two params are required. The first is the
email order number, starting from 1. The 2nd is the number of lines you want to display.

RETR This command displays the whole email. The only parameter is the email order number.

QUIT This commands tells the pop3 server to close the connection.