Windows 10 Mail App

Friends computer suddenly stopped getting her mail on August 25, 2018. In trying to restore to it's former state, it first reported that a problem was keeping it from syncing. After trying several suggested solutions, the last one (delete account and readd), after deletion, cannot add account back. I get various errors but the most common seems to be 0x80004005 which I cannot get past. How can I add her account back. Any suggestions--thanks in advance.