1. I've seen "mail in your application", but is it grammatical for "mail the application in"?-- Both are OK when using a noun, but only 'mail it in' is possible with a pronoun.
2. Why isn't "mail out", since you're mailing your application to the university, shouldn't it be "mail out"?-- You can mail it out from your house ('I mailed it out this morning'), but the univer