Setting up Windows Phone
Select add an account.

Select advanced setup

Enter your email address in the email address field.
Enter the password that you have created in the control panel
Select Next.

Select Internet email.
Enter your name as you want it to appear in sent emails.
Enter a name for the email account.
Enter imap.one.com:993 in the incoming mail server field.
Select IMAP4 as the account type from the drop-down menu.
Enter the email address in the Username field and enter the password that you created in the control panel.
Enter send.one.com:465 in the outgoing (SMTP) mail server field.
Make sure that the boxes for Outgoing server requires authentication and Use the same username and password for sending email are checked.
Make sure that the Require SSL box is checked for both incoming and outgoing email.
Select how often you want your phone to send/receive emails from the drop-down menu.
Click sign in to finish the guide.