I have a client using Office 365, fronted by the Outlook client on his MacBook Pro. He has created four personal groups of individuals in his Contacts list. Until last Sunday (24 March) he could send messages to these groups and the messages would show as 'sent.' Now when he tries, the status bar shows 'sending' but never really sends the messages to the groups. Further, the groups do not show up at all when he logs into his Office 365 account through the Web (thinking he could try sending through the Web login). Any ideas or thoughts on this sudden change in behavior, and as to why the Outlook client list and the Web list of personal address groups do not match will be deeply appreciated. Tried so far: creating a new group in the client but no luck sending from it either.