Solved Lost Email Address Upon Os Upgrade Macbook Air 11 Late 2010
Chosen Solution Macbook Air “upgraded” to “High Sierra” OS and somehow lost one of my two email addresses (same account). Attempts to reinstate it via “Internet Accounts” system preferences only results in message “unable to verify account name or password.” All suggestions on “fix” gratefully received! Turns out the answer to my problem is: If rebuilding the mailbox should fail, quit Mail.app and then delete “/Users/yourusername/Library/Mail/Envelope Index.” When you relaunch Mail....