To configure your email account with outlook Please Go to Tools from Menu Bar > Account Settings > New > Next > check the Manually configured settings or additional server types from bottom > Next > Next
OR
If you have already configured than Please go to Tools from Menu Bar > Email accounts
Your Name: Your Display Name
Email ID: Email-ID@yourdomainname.com
Account Type: POP3
Incoming Mail Server: mail.yourdomainname.com
Outgoing Server : mail.yourdomainname.com
Username: Email-ID@yourdomainname.com
Password: *******
After that click on more settings > Out going Server Tab > please check the Our server required Authentication then Go to advance> Please change the outgoing Server (SMTP) from Port 25 to 587.