Set up an SMTP Prevent Connectivity Check on windows?

Products

• Data Loss Prevention Network Prevent for Email
• Data Loss Prevention
• Data Loss Prevention Core Package

Issue/Introduction

Steps to set up an SMTP Prevent Connectivity Check on Windows

Resolution

The code

gethelo.bat is a DOS batch program that implements the code capture:

GETHELO.BAT

@ECHO OFF
REM This file makes a psuedo SMTP listener when run with netcat
REM nc -l -p 10025 -e "gethelo.bat HELO.txt"
REM HELO.txt is the name of the file that will be used to capture the data
FOR /F "TOKENS=1* DELIMS= " %%A IN ('DATE/T') DO SET DATE=%%A %%B
FOR /F "TOKENS=1* DELIMS= " %%A IN ('TIME/T') DO SET TIME=%%A %%B
FOR /F "TOKENS=1* DELIMS= " %%A IN ('C:\WINDOWS\system32\hostname.exe') DO SET HOSTNAME=%%A
ECHO 220 %HOSTNAME% psuedo SMTP MAIL Service, Version: 1.0.0.0 ready at %DATE%%TIME% -0700
SET/P Response=
ECHO %Response% > %1
exit

 

Run the capture
Execute the command:

nc -l -p 10026 -e "gethelo.bat helo.txt"

This will execute the SMTP listener software on port 10026 of your machine. This needs to match the resubmit port of the configuration of your Symantec DLP Email Prevent installation.

If the resubmit port is 25, then you'll need to do it like this:

nc -l -p 25 -e "gethelo.bat helo.txt"

So for this purpose, use a batch file that looks like this:

REM SMTPListenr.BAT listens to a port and responds like an SMTP listener
@ECHO OFF
REM This file makes a psuedo SMTP listener when run with netcat
REM nc -l -p 10025 -e "gethelo.bat HELO.txt"
REM HELO.txt is the name of the file that will be used to capture the data
FOR /F "TOKENS=1* DELIMS= " %%A IN ('DATE/T') DO SET DATE=%%A %%B
FOR /F "TOKENS=1* DELIMS= " %%A IN ('TIME/T') DO SET TIME=%%A %%B
FOR /F "TOKENS=1* DELIMS= " %%A IN ('C:\WINDOWS\system32\hostname.exe') DO SET HOSTNAME=%%A
ECHO 220 %HOSTNAME% psuedo SMTP MAIL Service, Version: 1.0.0.0 ready at %DATE%%TIME% -0700
SET/P Response=
exit 

 

Any breakdown in these connections will cause the connection to just drop.

See also: Article 159559: SMTP Prevent is not responding to Health Check

You can use a windows box for a connectivity check by following this method:

Tools
Get and install netcat or ncat for Windows.
Put the nc.exe executable in a directory that is on your path (or add the directory into which you placed the binary to your path).

Caveats

1) The Prevent server is in reflecting mode
2) The only thing being tested is the "connection" portion of the interaction