[stunnel-users] Stunnel Testing

Luis Rodrigo Gallardo Cruz rodrigo at nul-unu.com
Sun Sep 30 02:58:07 CEST 2007

On Sat, Sep 29, 2007 at 05:23:29PM -0500, Robert Lambrecht wrote:
> I am using a command line mailer (BLAT) from a batch file to notify me when
> errors occur.  My ISP requires SSL however still allows non-SSL traffic on
> Port 25 as well.
> I then use Stunnel with the following config:
> [smtps]
> accept = 25 
> connect = smtp.isp.domain.net:465
> Port 465 is the SSL port for my ISP.
> I run Stunnel as a service in Vista.
> I then have BLAT send an SMTP message on Port 25 to my ISP.  This works.

stunnel is listening on port 25 *of your machine*, not your
isp's. Thus, you need to have BLAT send it to localhost, port 25.

Better yet, to avoid confussion, have stunnel listen on some other
port (456 would be a good choice), and have BLAT send to 
localhost, on that port.

To check you're not sending anything on the clear, install a network
sniffer (wireshark is good) and have it show your network trafic to
your.isp.com. If you can read the mail in the displayed traffic,
you're sending in cleartext ;-)
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