Can sendmail listen for SMTP on two prots at once?

Christian Kratzer ck-lists at
Wed May 10 18:21:02 UTC 2006


On Wed, 10 May 2006, Marcin Jessa wrote:
> No need to run yet another instance of SMTP.
> Just use a little netcat trick for that.
> Install /usr/ports/net/netcat or use the one from base,
> put something like following line to /etc/inetd.conf and start inetd:
> x11             stream  tcp     nowait  root    /usr/local/bin/nc      nc -n -w 3 25
> This will accept connections to x11's port - 6000 and
> forward them to port 25 on localhost.

which will most likely create an open relay because the sendmail
will see the connection as coming from localhost. This will also
break logging as netcat will hide the real client ip from the 
sendmail  logs.

All in all very bad advice.


Christian Kratzer                       ck at
CK Software GmbH              
Phone: +49 7452 889 135                 Fax: +49 7452 889 136

More information about the freebsd-isp mailing list