Searching for all messages related to a specific conversation? You can do a manual search although it will likely take you several minutes at a minimum. Another option is to use the Related messages options. When you use the Related messages option, Outlook searches for all messages (received, sent, drafts, etc.) related to the conversation.

To use the Related messages option, right click a message within Outlook, point to Find All and click Related Messages. The Advanced Find dialog box opens and searches your inbox, sent folder, and drafts folder for any messages related to the one you selected.

[Photo above by Pete Reed / CC BY-ND 2.0]