New? behavior og rbl's

Alex Broens ms-list at
Fri Sep 23 12:23:12 IST 2011

On 2011-09-23 12:50, Jonas wrote:
>> Which translated means: - put your MTAs on dedicated IP/s and do
>> not share with gateway. - setup log watching/alerts - If you're
>> corporate/Exchange don't allow OWA without being VPN'd or at least
>> use a non standard port. - block port 25 outbound for all behind
>> the gateway which is not an MTA (your MTA is on dedicated IP) - use
>> outbound rating to minimize possible blasts.
> All sound advice for enterprises, however the part about putting your
> MTA on a dedicated IP is just nonsense. Here in Denmark 90% of
> companies have less than 10 employees, so most just run on business
> adsl lines or similar smaller connections, where there is only 1 WAN
> ip.

you get what you pay for... as simple as that.
(if a company can't afford a second IP or a clean smarthost then it has 
other problems)

> Who suddenly decided you need multiple WAN ip's to host a mail
> gateway?

nobody decided - it's just a piece of advice based on facts to spare you 
headaches (been there, got the tickets/listings/worries)

> In my humble opinion its taking it way too far when you combine
> things that has nothing to do with mail with a mail blocking
> filter...

get the picture:
pretend your IP spews bot spam by the thousands, maybe millions.

You honestly think anybody gives a damm if behind that IP there's also 
little mail server for a dozen of users, a cofffe machine and possibly a 
dozen own3d PCs?...  not really - block you and move on.
There's a +-130Mb XBL rbldnsd file full of IPs doing the same you were 
doing before you got listed.

We should be very thankfull that there's still BLs around like CBL/XBL 
which are extremely accurate, easy to deal with and so widely used that 
a listing should ring all our bells and trigger your "damm, gotta do my 

I agree it's a pita, but it's up to us admins to keep a clean 
neighbourhood and not let thugs abuse our little ecosystems.

.. and ranting won't get problems fixed any faster...


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