and want to add my Sheridan Office 365 account
PLEASE NOTE: there have been reported cases where users are sporadically prompted for their user name and password despite being connected to their Office 365 email accounts. To alleviate this behaviour, autodiscover needs to disabled in the Windows registry. The zip file linked below contains a file that will help you do this automatically.
Should you for any reason need to re-enable autodiscover on your machine, simply run the other file included in the directory – enable-autodiscover-2013.reg