Appropriate to email admissions tutor to aid in securing offer?

I am reapplying to a University that I fell short of entry into last year by a single grade, I am wondering if it would be inappropriate to e-mail them upon submitting my re-application and express my enthusiasm, as last year they were my first choice by a wide margin and this year I am working much harder to bring up my results so I am confident I will easily obtain their required grades. They have already told me that should I submit a strong application once more I will most likely get an offer again, however I want to do absolutely everything to ensure this happens because I loved the brief time I got to spend there. I'm not planning on begging or being distasteful, just stating that I am applying once more, that I enjoyed the visit and am working hard to improve my grades. If only to show that I am interested.