SMTP Relays...

[David V. Corbin]

>>> 
>>> Indeed.  But only fools react to open relays by 
>>> blacklisting an entire ISP domain, as (I think) ORBS has done.
>>> 

But what IF a major service provider was to decide to "reduce spam" by
prefenting ALL of their residential customers from accessing and SMTP server
but their own [the cable company's].....

This has actually happended here in NY. You MUST use their SMTP server!!!!
[they have blocked ALL outbound traffic on port 25 except to their IP!]