Just a quick post today. If one of your Office365 users suddently can’t login to Outlook 2010 (most often after password change) and you’re absolutely sure the password you’re using is correct, i.e. you can sign into outlook.office365.com and lync give this update a go: http://www.microsoft.com/en-us/download/confirmation.aspx?id=29361 . It’s worked a treat for me today!