You can select more than fifty items and/or select items across multiple pages from any list view in Outreach.
- Under the list view, click on the check box on the top of the page.
- A line will appear on the top of the page that states "All 50 items on this page are selected". You'll then see the option to "select all XX items".
- To select all prospects in your list, click the link that appears. The message on the line will change to reflect that all items in the list have been selected.