i just have a laptop with an internet connection, but i keep changing the internet provider. i want to be able to send mails from my laptop to real addresses. i dont want to use smtp. can i configure sendmail, or any other program to send mails from my laptop? i tried installing sendmail with "sudo apt-get install sendmail" but when i try sending mail, example through actionmailer in rails, of mail() call in php through a web program, the mail does not get delivered. what am i doing wrong, and how can i fix this?