SMTPAuth

Overview

SmtpAuth is a small program which is to be used in conjunction with email clients that do not support smtp authentication, but whose smtp server requires it. It runs in the background on the client's machine, accepting incoming unauthenticated smtp requests, and forwarding these to the smtp server, adding in authentication using a username and password supplied during installation. It runs as a service on Windows NT, or as a startup program on Windows 95/98.
Note : SmtpAuth only supports the plain-text authentication method. SmtpAuth assumes that the server will advertise that it supports plain-text authentication in reponse to a ehlo command.

Download

SmtpAuth 1.04 - Windows NT/2000/2003/95/98/ME/XP (62 kbytes)

Installation

  1. SmtpAuth consists of a single executable file smtpauth.exe. Download this, and run it either by double clicking on it or by typing "smtpauth" at the command prompt. It then prompts your mail server name, followed by your user name and password. Pressing < Enter > for the mail server name will use the default value of "mail".
  2. Once SmtpAuth is running, you must change your email client settings to indicate that your outgoing (smtp) mail server is now "127.0.0.1"
  3. Note: while SmtpAuth is installed, it will automatically restart whenver your computer restarts.
  4. To uninstall SmtpAuth, just run SmtpAuth again, and choose the delete option.

Configuration

In order to change the settings at a later date just run SmtpAuth again and choose the reconfigure option. By default, SmtpAuth assumes that your smtp mail server will be on port 25. If this is not the case, you will find a file "smtpauth.ini" in your windows system directory ("winnt\system32" on nt, or "windows\system" on win95) . Change the line that reads "mail_port 25" to whatever port your smtp server is on. SmtpAuth also assumes that it should listen on port 25 on the system that it is running on. This can also be changed by modifying the "port 25" setting in "smtpauth.ini". After modiying anything in "smtpauth.ini", you must restart SmtpAuth. This can be achieved by running SmtpAuth and choosing the restart option.

Example of What SmtpAuth does

The following are 2 examples of what a client might say and receive from SmtpAuth, together with what SmtpAuth actually sends on to the server. After the authentication has taken place, SmtpAuth simply forwards whatever the client and server say on to each other. SmtpAuth will hold off from responding to the initial helo, or ehlo command until it has received confirmation from the server that the authentication was successful.

Client to SmtpAuth Data, Example 1:
220 matt.netwin.co.nz DSMTP ESMTP Mail Server
helo matt
250 matt.netwin.co.nz. Hello matt (127.0.0.1)
.
.
.

Client to SmtpAuth Data, Example 2:
220 matt.netwin.co.nz DSMTP ESMTP Mail Server
ehlo matt
250-matt.netwin.co.nz. Hello matt (127.0.0.1)
250-ETRN
250-DSN
250 HELP
.
.
.

Here is what SmtpAuth would say and receive from the server for either of the above cases:
220 matt.netwin.co.nz DSMTP ESMTP Mail Server
ehlo matt
250-matt.netwin.co.nz. Hello matt (127.0.0.1)
250-ETRN
250-DSN
250-AUTH PLAIN LOGIN
250 HELP
auth PLAIN AHRlc3QxAHRlc3Q=
235 Authentication succeeded
.
.
.