Autor: W B Hacker Datum: To: exim users Betreff: Re: [exim] How to not reply to bad mail
lee wrote: > On Fri, Nov 21, 2008 at 06:52:42AM +0800, W B Hacker wrote:
>
>> whitelist the odd idiot who thinks the price of a Linux or *BSD CD makes
>> hime into a mail service w/o need of fixed-IP, MX and PTR RR.
>
> Is there an RFC specifying that you need a static IP and DNS entries
> --- or the other way round, is there an RFC specifying that receiving
> hosts can/should/must require sending hosts to have them?
>
>
..and to HELO with a FQDN [2], while we are on the subject..
Only since the original RFC 822
Much has changed, those 'basics' have not.
WinZombies can almost NEVER satisfy any part of that, let alone the
whole lot, so there's your first, cheapest, and most effective tool
against spam and WinCrobes.
Why you need a whitelist is 'coz folks who don't even bother to ASK the
question you just asked are configuring mailservers for paying customers
who refuse to believe they have a problem because '.. mail get through
to <others>...', while at your end you have equally clueless customers
who believe the problem must be your fault, as 'they say they don't have
a problem with anyone else..'.
At the end of the day, it is we (mailadmins) who created the spam
environment FOR the zombie farmers.
What we did was tell ourselves 'be generous in what you accept'.
Dunno WHY we did that when we surely would not have eaten s**t served as
steak just to 'be polite'.
Bill
[2] 'literals' are permitted, as in [203.194.153.81] - but many
sysadmins do not accept those, ELSE allow use only for traffic to abuse@
or postmaster@ . The most common need is to allow servers that do
specialized work not needed DNS entries to transmit their
daily/weekly/monthly cron reports.