As a follow up to yesterday’s e-mail, here is an article from Sept. 2015 and Kevin Hunt of the Hartford Courant.  It’s still relevant today.  

http://www.courant.com/consumer/bottom-line/hc-bottom-line-snet-email-20150921-column.html

The key point here is that there is no relationship between Frontier and your former ATT Yahoo e-mail.  As he says, the account will stay active for as long as ATT supports it.   Frontier will provide a separate e-mail.   Like me, he recommends an independent e-mail account.

He suggests a method at the end for setting up the Gmail account to check for Yahoo Mail.  That is one way to migrate.  There are other ways of making the transition.