In message <4461DFA2.9060009@???>, Marc Perkel <marc@???>
writes
>Gareth Hastings wrote:
>>> Just wondering how to do this. I'd like to test to see if the sending
>>> host at port 25 open. Would this be a good way to detect spammers?
>>>
>> Would
>>
>>> a host sending email to my host not have port 25 open to receive
>>>
>> email?
>>
>> I think this would be a bad test also. Often people who use smart hosts
>> or have outsourced spam/AV management tend to restrict access to their
>> mail servers to only the relevant hosts (i.e. upstream relays etc)
>>
>I wasn't going to use this test by itself. Just wondering if it could be
>done.
of course it can be done. It's just not in least bit sensible
>I was thinking of some way to examine the sender to see if it
>looked like it was a home computer running Windows XP as opposed to a
>server.
to do this effectively on a machine in the UK would almost certainly
involve you in committing an offence under the Computer Misuse Act 1990
your jurisdiction may vary
>And this was just one aspect of the test. I might look at ports
>135 and 139 and 455(?) etc.
this will trip intrusion detection systems all over the place. This
makes you part of the problem, not part of the solution :( It is also,
in these sensitive times, likely to make people more interested in legal
remedies and will certainly result in them pursuing matters with your
connectivity provider, or their upstream :(
>The idea being is this the computer has all
>the windows ports open and is not a Windows 200[03] server, and maybe on
>a dynamic IP then I might reject it. So the idea wasn't to just check if
>port 25 is closed, but check of 25 is closed and other ports are open.
Please go back to learning about email and stop fantasising. If schemes
like this worked then everyone would use them. They don't work, they
_do_ cause trouble and they should be avoided.
I wouldn't answer this on the list at all, but I think it's important
that dumb ideas can be seen to be peer reviewed. Otherwise, people
browsing the archives might think this idea worth pursuing. It isn't,
it's rubbish :(
- --
richard Richard Clayton
Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755
