Go to http://webmail.yourdomainname.com (no www in the URL)
Username = email address
Password =This is usually set to Password1 initially and you should change this as soon as possible inside the system.
I recommend RoundCube email – easiest to use I think of the three online email programs offered once you login.
If you’re setting your email up on Microsoft Outlook the servers are:
Pop = mail.yourdomainname.com (incoming)
SMTP = mail.yourdomainname.com (outgoing)
You can watch a video tutorial for this HERE.