How do I create a search folder for uncategorized mail in Outlook? There only seems to be a way to filter by "being in which category?", not by "not being in any category". I would like a search folder with mail with "no category".
The last comment from someone named Tyler gave me the key to do this.
You start by adding a new search folder from the Folder 'menu' (ribbon tab). (This is also where you can set "Show in Favorites" which makes your search folder part of the the that highlighted listing at the top in the 'navigation pane'.)
In the new search folder dialog you go to the bottom of the list, select Create a custom search Folder and click on Choose....
A new dialog comes up where you need to set Criteria.... You also specify the search folder name here.
When adding criteria, you go to the Advanced tab. Here you select the Field drop-down. (Here are every available information category, called 'Field', is listed.
You need, from the Frequently-used fields, the one called Categories. (You can also find it in the All Mail Fields field 'group'.)
For Condition (the type of the match) you need to select is empty from the drop-down list. (The Value to compare against / 'comparand' will now be blank and grayed out.) When you created a criteria, you Add to list. (You could define multiple criteria and add each of them to narrow the result.)
You are (almost done), of course you need to click OK and generally answer everything positively until you find your way back to Outlook (main view).
If you ever need to edit your search folder, right click it and select Customize search folder.
For example you probably want to go back to advanced criteria tab and add the Field from All Mail fields called In Folder. You can set the condition is (exactly) and the value