The MxSMTP module does generate a few errors when you first download it into a new project:

• There is a dependency on the community commons module. Please make sure you also add that module.
• The microflows in the "CONFIGURE ME" folder (which validate and process mails) have to be modified to call microflows in the rest of your model.

I believe both of these points are also explained in the documentation of the MxSMTP module, along with other configuration options and instructions. Be sure to read and understand the documentation, especially if you want to use this module in the cloud!