The Ju 86 was the less successful of the triad of bombers disguised as airliners of the nascent Luftwaffe. Equipped at first with Diesel engines made also by Junkers, those engines proved to be a total nuisance; later models changed to more conventional radials. It wasn’t enough. The better handling/performance of the Do 17 and of the even better He 111 cut short their operational career. The Ju 86 was nevertheless used in other roles -specially as a very high altitude recon and bombers- and were also modestly exported. One foreign user was the Swedish AF which kept them in service until 1958.
In this photo militarized Z’s exported to South Africa.