The following is an example of the setting for ECCS2016 (the setting is different from the MailHosting service).
After starting Apple Menu, click on "Add Account" in the "Mail" drop-down menu in the upper menu bar.
Select "Other Mail Account..." on the screen giving a selection of selecting email providers, and click "Continue".
Type in the user information as shown below once the "Add a email account" screen is displayed, then click "Sign In".
If the "Unable to verify account name or password" message appears (see below), complete the items as given below and click "Sign In".
When the process is completed, the screen for selecting applications to link will appear, make sure that "Mail" is ticked and then click "Done".
The setup process is complete if the new account is added as shown in the picture below.