drauk and naples, I think (if I may interject) that you are being a bit harsh on carrier and not fully understanding his problem. I don't thonk it is the cafe or its isp that are doing the blocking
Certainly the claim made in the advertising for pprune mail about them being globally accessible, permanent and versatile would not appear to be totally accurate.
As I understand it, Pprune email is web based, meaning that it won't be using smtp until it leaves the everyone.net servers, so blocking of smtp at internet cafe level does not come into it.
If the failure message is coming from everyone.net, then all they can be doing is checking the ip address of the internet cafe against a list they are holding, and thus deciding to black it.
So, either the list held by everyone.net is wrong - which could be the case given that yahoo works - or the isp that the cafe use has indeed given air timeto spammers, and everyone.net is totally correct in the statement.
It would be nice to be able to have a dialogue with everyone.net about their (rather crude) blocking methodology, but in the meantime you could access your mailbox through something like
www.mail2web.com and see if that helps.