A: This question has a really easy answer: Yes. And it comes with an interesting example.
By default, the search settings in Outlook 2010 and Outlook 2007 use yellow highlight to show your found search terms in the results. This setting can be configured within Outlook 2010 by selecting File, Options to get to the Backstage view, then choosing the Search option in the left pane. You can also access these options by selecting Search Tools, Search Options on the Search tab, which itself is visible only when the Search field is selected in Outlook. In Outlook 2007, go to Tools, Options, then click Search Options.
Figure 1 shows the Outlook 2010 interface where you can toggle on or off the option to use highlighting for search terms in results and, if on, select the color for Outlook to use for highlighting terms. Search terms are then highlighted in the results whether you query mail items, calendar, contacts, tasks, and so forth, and also when you use advanced search settings.
I worked with a customer from an HR department who used the yellow highlight functionality in many of her email messages to place visual emphasis on words. When she performed searches of her messages in Outlook that included searching the message body, the results would highlight the search term -- but also keep the highlights she used when composing the messages. This sometimes made it difficult for her to identify the search term highlighted in the search results.
The solution was to change the search term highlight color and not to use that color as highlighting when composing messages. Incidentally, if the search term is an already-highlighted term in the message body, the search highlight color overrides the color that was used to highlight the term in the message.
This whole problem might explain why I still use bold or italics to emphasize words instead of highlighting.