The Coaches Console system prevents the coaches from using Yahoo and AOL email addresses in their Communication Settings due to delivery issues. When such an email address is entered by the coach into the fields, a message is displayed that details the reasons why the Yahoo/AOL addresses are not supported:
"Please use a different email address as your Coaches Console email.
This email address is used to send out important communication to your contacts.
AOL and Yahoo do not allow third parties such as Coaches Console to send email on their behalf, resulting in your communication to your clients not being received."