This field can be found by first opening the 'Endpoints' form in Basic->Setup->Application Integration Framework, then highlighting the Endpoint in question, clicking 'Action Policies', highlighting the outbound action in question, clicking the 'Configure' button, and clicking the 'Setup' tab.
By default, this field is set to 'Yes', which means that AIF will only output the first 1000 records of any AIF outbound transaction where there are more than 1000 records.
Microsoft product screen shot(s) reprinted with permission from Microsoft Corporation.