[Exim4U] can connect to my pop to get mails but can't send emails

Hi After days of checking and cross checking, i still cant send emails with my new setup. i have not setup webmail on my server yet. i can connect and download my emails from my mail server but can't send emails am using icedove client. the error i get always is: 'Sending message failed. The message could not be send because connecting to SMTP server <myserver> failed. The server may be unavailable or refusing connections. Any idea what am doing wrong. Kebba