"Mark C. Langston" <mark(_at_)bitshift(_dot_)org> wrote:
By "they", do you mean the end-users, or the ISPs?
Everybody.
my example was meant more to highlight problems introduced by the
intermediary transit (the ISP, e.g., via a transparent proxy) than
by the end-user or the administrators of the end-user's desired MX
(or, more likely, by policies the administrators must obey).
The intermediate policies are chosen to prevent end-users from
abusing network resources. e.g. Blocking port 25 outbound is an
attempt to stop end-users from sending spam.
Both (ab)use, and policy, are hacks to work around lack of a
technological solution, or lack of deploymenty of a solution.
This sounds as though you believe all the power lies with the end-user.
In many instances, the end-user is powerless to effect change in the
intermediary ISP
If the end users have alternative methods which are accountable, the
ISP's policy can be relaxed to permit those methods.
I'd prefer everyone move to secure, authenticated mail exchange, but the
reality is that it hasn't occurred. Getting organizations --
particularly large ones -- to make widespread client-side changes would
be difficult.
They upgrade laptops regularly. So there's already an existing
model for deploying software upgrades. Wait 2-3 years, and deployment
will have reached the majority of users.
Alan DeKok.