Hello, My internet service provider is Belgacom Skynet (Belgium) the port 25 are filtered I make .muttrcskynet to check my mailbox in pop3 with mutt The problem is all mails works correctly but when i send a mail error to an user unknow i don't receive the mail error says "user unknown" what's the matter? is it maybe because my isp filtered the port 25? Have a nice day Frederic