Mark Foster blakjak at
Sat Apr 7 01:42:23 CDT 2012

On 07/04/12 05:11, David Miller wrote:
> RBLs don't block emails.  Operators of mail servers who use RBLs block
> emails (in part) based on information from RBLs.

If only one could convince end-users of this fact.  More often than not,
end-user simply sees the company that they pay to provide them with
email service, unable to provide it. 

> Noone has a "right" to send email to anyone else.  Email is a
> cooperative agreement between sender and receiver.  The receiver agrees
> to accept the email, but at any time and for any reason the receiver can
> stop agreeing to accept emails from a sender.  It is completely legal to
> decide not to accept (i.e. block) emails from a sender.

Absolutely true.  Of course, for the vast majority of end-users, they're
simply expecting to be able to exchange email with anyone that has an
email address.  There's no connection between the end user, their local
mail service providers administrators, and the decisions they make about
who they'll exchange email with. Nevermind trying to make connections
between mail service providers...

> RBLs are not beholden to senders.  RBLs are beholden to the receivers
> who use their RBL to preserve the quality of the RBL.  RBLs are a
> meritocracy.  If an RBL either lists too many valid senders or does not
> list enough bad senders, then receivers will notice and stop using the
> RBL on their servers.
Or receivers will be oblivious, and simply not care.  (They don't know
what they're not receiving).

Consider an MSP with say, 1 Million mailboxes.
What proportion of those customers are going to need to be affected by a
poor RBL-based decision,
and what proportion of those are going to be motivated to complain,
and what proportion of those are going to get the attention of the right
and what proportion of those will count for enough that the relevant
beancounters see fit to change their RBL usage?

Whilst i'm sure there's some players out there bucking the trend, the
reality is that the senders MSP wind up carrying a lot of the cost; they
have to find an out-of-band method of engaging the receiving MSP,
advising them of the predicament, and justifying some sort of exception;
they also obviously have to be seen to try to get off the RBL (and we've
seen how hard SORBS, notably, make this) and the receiving ISP can fall
back on the 'well everyone else is fine, so the vast majority of our
expected inbound email is fine, why should we care about you, and change
our behavior because of it?' ....   Sending MSP then has to try to
explain the reality to their customer, and risk losing business because
their competitor isn't (right now) having the same problems...

Bottom of my rambly-line is that as a major point of issue with your
post; you're posting the position of the Network or Mail Service
Operator as it 'should' be, but not indeed how it actually is, in practise.

(And FWIW I agree with the poster who pointed out that RBL's would be
unnecessary if network operators took responsibility for the behavior of
their networks (ala their customers).  The small players are usually
pretty damn good. It seems that the bigger you get, the less you care
about issues that affect a smaller proportion of your scale.

Which probably explains the attitude that several of the big players
take around rejecting email due to obscure reasons...


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