MIT Admissions Questions

Hi,
I am a sophomore interested in applying to MIT and I have a few questions. I started a new thread because the OP on the MIT FAQ discussion has not been on CC in almost a year.
If I apply as a junior and do not get in, can I apply as a senior?
How many people get mail from MIT without having a myMIT account? (I signed up for one after I received the mail).
Do I have to complete all my high school credits to apply to MIT?
Thanks in advance,
KG5APR

yes you can apply as a junior and senior.

mail question not relevant to admissions.

MIT does not require you to graduate high school but they expect you to be really good in terms of your depth in science and math for you to be accepted without one.