A lot of users end up frustrated and confused when they try to use multiple "doesn't contain" rules in a filter (even I sometimes have trouble with the logic.)
When you use "doesn't contain" with two different values, such as "From doesn't contain Mary or Bob", you are asking the filter to do something if either of the conditions are true:
If From doesn't contain Mary
OR
If From doesn't contain Bob
and since everything except Mary's message are not from Mary, and everything, including Mary's messages, are not from Bob (except Bob's messages), the condition is always going to be TRUE. Outlook is processing the rules as "(if not Mary) OR (if not Bob)", not "if not (Mary or Bob)".
You need to use 'if not in Team1 AND not in Team2' – but when you use the same field twice, it is always OR'd. You need to use AND when you are using 'not' operator.
If you need a better filter, you can enable Query Builder.
Categories add a special twist since they are a text field. Normally, you can use two or more values in the Value field – mary OR joe – or mary, joe – but because categories is a text field, if you use OR, it thinks you are looking for the phrase 'A OR B', not A or B.
Published June 5, 2012. Last updated on May 8, 2014.