Open Telnet (Start – Run – CMD – Telnet) and write the following line:

TELNET Servername.Domain.TLD 110 (in our example TELNET London.nwtraders.msft 110).

- The Exchange Server accepts Connection to Port 110

Exchange Server 2003 POP3 - It is a Exchange 2003 Server

Version 6.5.7226.0 - The Exchange Version Number

London.nwtraders.msft - The FQDN of the Exchange Server

These are some helpful information about our connection.

Let’s go further:


What do we see here?

USER MSEXchangeORG – The name of the user to connect to the mailbox

PASS Fake001 – The password of the user (transmitted unencrypted over the network)

LIST – Lists all E-Mails in the mailbox

RETR 1 – Display the selected E-Mail

A very interesting part is the displayed body of the E-Mail. You can see the encapsulation of the E-Mail, MIME type, Message ID and much more helpful information.

POP commands

USER


The User you would like to connect to

PASS


The password of the user (transmitted unencrypted over the network)

STAT


Overview over the POP3 mailbox

LIST


Displays every message in listform

RETR


Displays selected message (RETR 1)

DELE


Deletes selected message (DELE 1)

NOOP


NO Operation

RSET


Undo DELE function

QUIT


End POP3 Session
Connecting to SMTP

Open Telnet (Start – Run – CMD – Telnet) and write the following line:

TELNET Servername.Domain.TLD 25 (in our example TELNET London.nwtraders.msft 25).


SMTP supports two verbs: HELO an EHLO

The HELO or EHLO verbs in SMTP are how the client identifies itself to the server. Clients that use single-label domain names, or domain names that the server cannot look up in the DNS database, are broken or misconfigured.

EHLO is the successor of the HELO verb and supports many more commands. The supported EHLO verbs are different from Mailserver to Mailserver. Exchange 2003 supports the EHLO verbs .

A very important EHLO verb is AUTH. AUTH lists the supported authentication methods for connecting to the SMTP Server. Exchange 2003 supports GSSAPI, NTLM and LOGIN.

Some ISP SMTP servers doesn’t support AUTH. They use SMTP after POP. SMTP after POP authenticates a user through a successful POP3 connection and lets him use the SMTP protocol with the applied credentials through the POP3 connect.

In our example we use the basic HELO command to connect.


What do we see here?

220 London.nwtraders.msft - the Server listens on the given SMTP port

Microsoft ESMTP Mail Service - This Server supports Extended SMTP

Version: 6.0.3790.0 ready - This SMTP Service is hosted by Windows 2003

HELO - Initiates connection (requires domain name by most SMTP

servers)

250 London.nwtraders.msft - Server accepts connections on IP address 192.9.200.116

MAIL FROM: Name@domain.tld - The Sender of the Message

RCPT TO: Name@domain.tld - The Reciepient of the Message

DATA: - Input e-mail data for subject and body

SUBJECT: - the subject line of the message

Enter the data for the message body. At the end of the message click <CRLF> “.” <CRLF>

The message will be transmitted through the destination address through exchange.

SMTP commands

HELO


Identifies the Client

MAIL


Specifies Mail Sender

RCPT


The Reciepient of the message

DATA


The Data part of the message

RSET


Resets message transmiting

VRFY


Verifies e-mail address

EXPN


Expand a mailing list

DSN


Delivery Status Notification

HELP


Displays help

NOOP


NO Operation

TURN


Mail TURN

ETRN


Extended TURN

VERB


Verbose Mode

QUIT


End SMTP Session

Please complete the following information:

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