There are some candidates, due to various unavoidable reasons, cannot submit MSPE to ERAS. ECFMG provies 'neutral MSPE' for them. This is from ECFMG website :
If you are unable to secure the MSPE from your medical school, you must indicate this on page 12 of your Common Application Form (CAF). A neutral placeholder letter will be provided in place of the MSPE. The placeholder letter will be provided to all of the programs to which you apply, and will state, “This is in lieu of an MSPE.” This will ensure that your application will appear as complete for those programs that require an MSPE before considering your application.
Its advisable to use this service ONLY if you are unable to obtain MSPE letter from you med school !