@Gkirko -- what risk for public in 25 port rule? Does it hurt anybody (may be only somebody feelings)
Mail-filtering, via blocking spammer's access to 25/SMTP is a good thing, if it blocks "phishing" E-mail targeted at your grandmother ("Hi granny, I am in Europe, and I lost my credit-card and airplane tickets, and I need you to use Western Union to send $1000 to me, so that I can pay the hotel, and buy new tickets to return home").
So, is your granny a "nobody" ? When you tell her that she has been "phished", will that hurt her feelings?
granny is responsible for herself.
Her family is responsible for her.
Someone could knock on her door & coerce her into giving them money
Is Shaw going to take responsibility for granny by placing a guard at everyone's door??
@Usrnm -- Is Shaw going to take responsibility for granny by placing a guard at everyone's door??
Shaw has already done that, for her computer.
If her computer is compromised, Shaw's port-blocking will prevent the computer from sending directly to "other" SMTP-servers, e.g., Bell, Telus, Hotmail, Google, with a flood of "spam" messages that bypass the spam-filtering and spam-blocking that is done by Shaw's SMTP-server.