AT&T Yahoo Email Sub Account mailbox unable to Synch
Suddenly, my AT&T Yahoo email sub account mailbox is unable to synch, while the main email account is working properly. I received the message "This mailbox is not synching with Yahoo and needs permission to resume. This can happen because a security setting or password has changed." There has been no change in either, and I am unable to send or receive messages on my sub account mailbox. This situation is occuring on my Windows 10 PC and my Apple phone, thus it is not an issue with my devices. Any help would be appreciated.