State Department officials were never sure what to make of a special tech assistant who former Secretary of State Hillary Clinton brought in as a political appointee, according to email exchanges that took place at the time.

Those exchanges were included in a newly unveiled letter that Republicans on the Senate Judiciary Committee sent last week to Patrick Kennedy, the department’s under secretary for management. Lawmakers are trying to find who in the department, if anyone, participated in the oversight of a private server that Clinton used to process her email.