Outlook 2016 Conditional formatting problem with "is not empty" and categories


Outlook version
Outlook 2010 32 bit
Email Account
Exchange Server
I made a conditional formatting rule to change the font on messages that have any Category assigned. I set the query as "Categories" and "is not empty." Guess what? It applies the formatting to every single message. I troubleshot the issue by unchecking every single other rule and it still does this. I also verified that the messages do not, in fact, have categories assigned and they don't.

Can anyone else confirm this behavior?

How can I apply a rule to any message that has a category assigned?

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Another person had the same problem a couple of months ago. I couldn't repro it using their steps - they came back and said it only happened if show as conversation was enabled. I could repro it then. (I normally use show as conversation so its weird that i had it off.)

Rather than using is not empty, try using letters - if you use real words in category names, you can use just the vowels:
categories contains a,e,i,o,u,y