Fake MTA

Steve Holmes steve at holmesgrown.com
Sun Aug 11 10:13:44 EDT 2002

If you are not going to use this machine for anything productive mail
forwarding, why not just block port 25 with something like endoshield
firewall script? If you are going to serve local mail with it, I would
urge to go with the latest version of sendmail since blocking of
outside mail relay is blocked, almost too well.  I have had some bad
experiences with this feature and fetchmail where someone's incoming
mail won't reverse dns lookup and cause further fetches to fail.
That's a long and hard story to explain but I've had to relax that
sendmail restriction to allow relaying from outside my domain to get
fetchmail to successfully pull down the pile of mail from the inbox
and then restore it until the problem comes up again.  I use my
fetchmail procedure merely as a backup to my direct addressibility
when my machine is off line for any reason.

Hope this rambling makes some sense.

On Sun, Aug 11, 2002 at 05:21:58AM -0400, Joseph Norton wrote:
> Hi listers:
> Recently, I brought up an old version of Linux on my 486 just to see what
> it was like.  I telneted into it and everything went all right.  That is,
> until, someone started scanning the ports on the old system and found out
> that port 25 was open.  You can guess what happened...  They immediately
> tried (and as far as I know succeeded) to send out a piece of spam which
> my older version of sendmail happily forwarded.  Now, before you tell me
> that later versions of sendmail (I believe 8.9 and after) do not allow
> relaying by default and that I shouldn't have been playing around with
> older software, let me explain the reason for relating this.
> ...

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