[prev in list] [next in list] [prev in thread] [next in thread] 

List:       exim-users
Subject:    Re: Expirable addresses [was Re: Year 2000. ]
From:       bnb-867225209 () news ! looking-glass ! org (Brian Blackmore)
Date:       1997-06-25 7:53:29
[Download RAW message or body]

This may be a little late I've been busy, however since I wrote the
original driver that encouraged the change its probably worth commenting
on the reasons.

The driver was designed to stop people trawlling usenet automatically
and grabbing addresses, its designed to work with a small patch to INN
that automatically adds the suffix on outgoing news postings that don't
already have an address.

It was not implemented as a filter for the following reasons..

1) Performance, my mail machine is till at 386SX 16Mhz.
2) The facility to accept this type of mail had to be available to all
   users automatically, since an address could be "timed" for any user.
3) The facility was to be active on one domain only, I considered a global
   filter file to be inappropriate.

On my system presently the following occurs,

Outgoing messages are by default addressed
    <username>@looking-glass.org
News postings are addressed
    <username>-<timed-suffix>@news.looking-glass.org

Suffixes are valid for all users in the domain looking-glass.org, thus by
default <username>-anything@looking-glass.org works. Addresses in the domain
news.looking-glass.org get aliased to <username>-news@looking-glass.org and
are then delivered as normal, so long as the address has not expired.

I freely admit this is *not* a fully watertight spam blocking mechansim, I
don't believe such a thing exists. It does however have the following
advantages:

1) Use of an expired address is an explict statement by the user that "they
   do not want spam", as is something like the mailing preference list for
   snail mail. Those spammers who are actually advertising *may* actually
   take notice of it, since they can be sure these people are not interested.

2) At the moment, and probably for a good couple of years it does provide a
   spam blocking mechanism.

-- 
Brian                                        http://www.gryphon.demon.co.uk/

[prev in list] [next in list] [prev in thread] [next in thread]