but it's just login and then logout, right!?!?
Yep, just repeat the same process for each account you have.

As for ICMail, I haven’t tried them yet but maybe they might be a good alternative. Although they seem to focus a little bit more on e-mails rather than uploads???

Anyway, I don't mind ...

Yeah 4shared is great; I like its unlimited download bandwidth. Only bad thing might be that only one person can download the same file at the same time (for the free accounts). But nowadays most people have decent connection speeds so it shouldn’t take long for a download slot to become available ...