To continuously advance electro mobility, a holistic approach to electric machine design is needed. Optimized designs allow for efficient energy transformation, from electrical to mechanical energy, and thus increasing the vehicle range. A critical aspect in this regard is a well-designed and sized cooling system. While there are various cooling strategies applicable to e-machines in automotive applications, for now liquid-cooled concepts attract the greater interest. With the trend of compact design and high-power density electric machines, the oil spray cooling is gaining the interest as a standalone cooling strategy or applied in combination with liquid-jacket. The development process of electric machine consists of multiple stages, ranging from concept and design of components, to the integration and verification of the entire system. To save resources and improve efficiency of the process, usage of simulation tools can be highly beneficial. Ideally, creating a digital twin in form of the simulation models can accurately predict the behavior of the system and its components, allowing engineers to cover nearly all scenarios relevant for the product. On the system level, development of Vehicle Thermal Management System (VTMS) and relevant sub-systems give us important information about the general energy balance and validate the integrated cooling concept. However, on the component level, the optimization of the geometrical properties of coolant supply, as well as flow conditions can greatly benefit from the means of Computational Fluid Dynamics (CFD) analysis. This study presents a computer simulation workflow for predicting the coolant and structural temperature distribution in an e-machine. The workflow considers a comprehensive multi-domain geometry, simulating the coolant flow and heat transfer between fluid and structure components in a single CFD model. The boundary conditions, in form of heat sources, are determined based on previous electromagnetic simulation. The simulation not only provides the input data for CFD simulation, but also automatically creates an equivalent 1D thermal model. Great benefit originates from the fact that 1D model and CFD simulation have consistent thermal modelling capabilities and can be used to validate the design and predict outcome of any design changes. Ultimately, the two simulation models allow the comparison of different machine designs and operating conditions with respect to the probability of incurring component damage due to the thermal overload.