An Outlook user asked a question at Outlook Forums: “I have been trying to figure out how to add a tick box for outlook inbox view for every message line, one that I could myself tick and use for sorting?”
Jorma is looking for a way to make Outlook work similar to web-based accounts, where you can click in a checkbox then do something with the selected messages.
You can do this in any version of Outlook using a Yes/No custom field.
1. Right click on the row of field names, choose Field Chooser.
2. Click New – add a Yes/No type field and use icon format. (Enter a name for the field too.)
3. Drag your new field to the row of field names
4. Enable in-cell editing (in Customize view, Other settings) so you can click in the field to enable or disable the checkbox.
After checking the boxes (checkboxes may not appear in the column until after you click in the field), sort by the column and select the checked messages then move or do whatever with the selected messages.
While you can use Ctrl+click to select multiple messages, using checkboxes allows you to make the selection as you work and act on it later.
(Jorma’s thread is here: http://www.outlookforums.com/showthread.php?72884-How-to-add-sortable-tick-box-to-Outlook-2003-inbox-view )