Re: [Exim] A couple things before I start my Exim migration

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Autor: Nigel Metheringham
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Dla: exim-users
Temat: Re: [Exim] A couple things before I start my Exim migration
[No recipe answers here, but a few pointers]

On Thu, 2004-05-13 at 08:08, Tom Wiebe Lists wrote:
> SpamTraps - SIMS allows you to designate certain addresses as spamtrap
> addresses and any host sending email to one of these addresses (which I
> disseminate widely) blacklists the sending server for a short time. A
> simple yet remarkably effective anti-spam measure. Is there a way to do
> this on Exim. I believe Stalker's CommunigatePro does this as well.


Not directly. It could, however, definitely be worked round. Spamtrap
addresses aliased to a program invocation (probably with the sending
host as a parameter to the program). The program (most likely a perl
script) would update a dbm file keyed on sending host and having (say) a
timestamp as the data. You would also have a regular cron job which
walks the dbm file and removes stale entries (thats why you put the
timestamp in the data). Use the dbm file as a host blocklist in an acl.

> Blocking Address Harvesters - When an attempt to send email to a number
> of invalid addresses is made, the sending server is temporarily
> blacklisted by SIMS. Another simple, and effective anti-spam measure.


Probably similar form to the one above. Be very careful, though, about
having blanket address acceptance.

> Throwaway email addresses - I have a router entry in SIMS that will
> send any email addressed to user.<whatever>@domain.com to
> user@??? on the server. I use this extensively to sign up for
> stuff and, if the address gets abused, can route it to error and I've
> blocked a bunch more spam. I've tried using an alias for this, to no
> avail, thinking this is likely a router? Any pointers in setting this
> up would be most helpful.


Look at local_part_suffix (and local_part_prefix) in routers and
transports documentation. These are also available in filters which
allows you to do per user designation of these.

    Nigel.


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[ Nigel Metheringham           Nigel.Metheringham@??? ]
[ - Comments in this message are my own and not ITO opinion/policy - ]