Group by Category disappeared
I have been flagging emails in Outlook and adding a Category with the name of someone who is responsible to deal with the content of that email. This gets automatically added to To Do and when I move it from my flagged email list to a proper list, I have been able to group all of these email tasks by Category. It's been working great and my team can see their own tasks easily by grouping by Category. For some reason, this option disappeared yesterday and I can't find it anywhere. Does anyone know how I can get the Group By Categories option back or where else I should look for it?