Several E-1s were rebuilt as E-2 or E-3, at least three E-2 and one E-3 were used by DVL and Hansa-Luftbild GmbH (Hansa Aerial Photography Ltd) in a secret military reconnaissance role prior to the war.
Viacero Do 17E-1 bolo prestavených na verzie E-2 alebo E-3 a prinajmenšom tri E-2 a jeden E-3 boli používané spoločnosťou DVL a Hansa-Luftbild GmbH, na tajný vojenský prieskum tesne pred vojnou.