Hello,
In Dynamics 2015, when you exported data to excel, made the changes and then imported it back, if the file was in the same format as you exported it Dynamics would recognize it as a re-import and you would not need to do any manual mapping.
Has this feature been removed in 2016 on prem? I have just tried to follow the above steps and I am being asked to manually map.
Thanks,
Tanya