It's an easy anti-spam measure for sure, but there's no reason you (as the user) shouldn't have a checkbox allowing you to remove this limitation. Otherwise it's not a full internet access.
There's a good reason: The demand for it is infinitesimally tiny, and the hassle of doing so (and having to deal with monitoring whether or not you end up being a spam source) is an extra cost.
An argument that it's not "full" internet access will get you nowhere - very few consumer internet subscriptions are "full" internet access in the sense that they are totally unrestricted - most have very severe restrictions on e.g. running servers and many other things.
I'm not sure I understood you correctly. Are you saying it's a common thing for all "ISPs" in the US to block outgoing traffic on port 25 (and allow incoming traffic for Outlook et al.)? Or do you simply mean that most email providers will block incoming mails from residential IP adresses?
My provider (BellSouth or AT&T or whatever they're calling themselves this week) block incoming port 25 and block outgoing to port 25 to anywhere except their SMTP servers, because of spam.
Words mean what people use them for. Sure it's technically only 65534/65535 of an ISP, but that's not a very useful way to communicate with people about the issue.
If you are not allowed to run server, they are WSP (Web Service Provider) not ISP.
But if you are OK with ISP not providing internet, I'm sure you are fine with unlimited limited or throttled after x, 24/24 access between 9-5 and secured http page as long as there is a padlock favicon ...
> Words first mean what is written in a dictionary or encyclopedia.
Nope - this is an important difference between English and other languages. If what people say differs from what's in the dictionary, it's the dictionary that will change, not the people.