I've been using Advanced Find to locate people who meet certain criteria. After I find them, how can I send a message to only those people?

One solution is to use a filtered view rather than Advanced Find. If you periodically need to locate the same contacts, you probably need to create a new view. To do so, choose View, Current View, Define Views, then click New. After you enter a name for the new view, you'll see a dialog box with different customization tools. Click Filter to open a dialog box with options that look much like the Advanced Find tool's options. Filter the view so that only the contacts you want appear. You can then select all the visible contacts and use them in a mail merge or use the Actions, New Message to Contact command to send a message to all the contacts at once.

The main difference between using a filtered view and Advanced Find is that a view shows data in the current folder only, whereas Advanced Find can search multiple folders in your mailbox. If you need to search across several folders in your mailbox, you need to use Advanced Find. After you find and select the contacts you need, choose Edit, Categories from the Advanced Find dialog box's menu bar to add a common category to those contacts. You can then go to each folder, choose the By Category view, and select the category you created. To send a message to the selected contacts, choose Actions, New Message to Contact.