The M15 is part of the tax return, so it needs to be mailed with the rest of your state tax return.
If you are sure that the information on it is incorrect, you may want to contact Customer Support. However, in the event it is a program error, it won't be fixed anytime soon. But as I mentioned before, if you are required to use the "Regular Method", that isn't eligible for e-file even if it is populated correctly.
