If you click on Preferences in the upper-right corner of the screen, you can change the page size between 20 & 200 entries per screen.
Article ID: 385
Last updated: 16 Jul, 2014
Information Technology Services -> Outlook -> NetMail Archive Reference Guide -> Why can I only see 20 records in NetMail Search? https://www2.owens.edu/faq/entry/385/