eWall

Transparency Module (EWLSP)

As with any proxy, eWall shares one common disadvantage: the email senders SMTP servers IP address will be hidden behind eWall. This may be good in the case of web proxy, that hides the originating web surfers IP address and thereby provides some privacy, but in the case of a mail server is less than optimal. As a result, your mail server may lose the ability to utilize it's IP based protection mechanisms, as the mail server will always see the eWall's IP address (Fig.1), and as a result all arriving emails always have eWall's IP address in their header.

169.254.33.234

127.0.0.1

Fig. 1: Working without EWLSP.


Fortunately, we have developed a unique Transparency Module (EWLSP) , that can be used to get around this limitation. EWLSP stands for eWall Layered Service Provider (more information about Layered Service Providers can be found here). This is an optional plugin, that transfers the originating senders IP address directly to the mail server application to re-enable the usage of your mail servers IP address based utilities.

169.254.33.234

169.254.33.234

Fig. 2: eWall with EWLSP.


Limitations & Cautions

Although EWLSP is well-tested and stable, it may not work under all circumstances:

  • Currently, both eWall and the mail server must be installed on the same machine. However, we are working on a new version of EWLSP, that avoids this limitation and can be installed anywhere;
  • If you already have software installed that already includes some other LSP (some antiviruses, firewalls or network monitoring software), EWLSP may interfere with it and results may be unpredictable. To make sure there's no other LSP installed on your machine (except default Microsoft's LSP), you can use this free LSP-Fix utility. This utility also can be used to repair a damaged Winsock stack.
  • In any case, if you notice any strange behavior on your computer after installing EWLSP, simply uninstall it using the LspInstaller.exe utility in your eWall directory, and proceed to use eWall in the standard way.