Re: Open Proxy - how do I prevent it? (long mail)

From: DaveK (no.spam@my.mailbox.invalid)
Date: 04/04/03


From: "DaveK" <no.spam@my.mailbox.invalid>
Date: Fri, 4 Apr 2003 14:35:06 +0100


"Thomas Rokamp" <mail@crax.dk> wrote in message
news:9ajq8vkeldoq4nt2rkibuonm6javs2uv2c@4ax.com...
> Hi!
>
> I have been told from several places, that my dsl connection at home
> responds as an open proxy.
[snip]
> Anyway - it is forwarding the following ports to my server :
[snip]
> 25
[snip]
> And thats it! As far as I can see, none of the above ports are related
> to any kind of proxy.
[snip]
> Qmail for smtp (25)
[snip]

  At a guess, your smtp server is probably accepting mail from and to any
address on the net - i.e. it's probably acting as a relay usable by
spammers. Unless you have a good reason to be offering an SMTP service to
the world at large, you should probably block port 25; if OTOH you're
running your own MX there should be some way to configure qmail to only
accept mail destined for your domain.

       DaveK

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