Fortunately, Outlook has a better memory than I have, and even more fortunately, Outlook makes it particularly easy to find all mail from a certain sender quickly.
Find All Mail from a Sender Quickly in Outlook
To find all mail from a particular sender quickly in Outlook:
- Highlight a message from the sender in any folder.
- Select Tools | Instant Search | Messages from Sender... (or Tools | Find | Messages from Sender... in Outlook 2003) from the menu.
Outlook will immediately show you all mail from the same sender.