I am a US citizen and have two US passports. They are both currently active. I am moving to Spain as a student and have therefore applied for student visa. Unfortunately the visa process is going to take 3 weeks and I leave to Spain in 2 weeks. I wanted to know if it is legal to enter Spain with my secondary passport and then have my passport with the visa mailed to me. I would then exit the Schengen area with my secondary passport and reenter with my passport with the student visa.