Sending mail to remote users.
I'm wondering if you guys could help me with a little issue i'm having, I followed the tutorial on digital ocean of setting up postfix for my server. And it seems some people are not receiving the emails that are suppose to be sent to them. I have ubuntu 12.04 and i'm using postfix. I have not been able to send emails to aol.com emails or aol.nl emails. I have tried both with the PHP mail() function, and sendmail through the command prompt and both of them do not work.