How to tell IP address of remote machine?

[Bruno Wolff III]

On Sun, Oct 25, 2009 at 14:17:48 +0000,
  Timothy Murphy <gayleard at eircom.net> wrote:
> Sam Varshavchik wrote:
> 
> >> I had a little program which I ran each day
> >> as a cron job to mail me the IP address of a machine
> >> in a different country.
> ...
> >> In any case, the program has ceased to work
> >> because the site heliohost seems to have gone off-line.
> 
> > You don't need to use any site. The sender's IP address will be recorded
> > in the test message's headers.
> 
> Thanks very much for that suggestion.
> I've looked at KMail showing all headers,
> and there are a couple of IP addresses which could be the correct ones:

If your mail is going through the ISPs mail server, then it could potentially
do things that make it hard to get the IP address you want.

You could note other kinds of direct connections to your machine. For example
you could note http connections to a url at your machine that isn't
published or discoverable.