Referring to the candidate in a recommendation letter I'm writing a recommendation letter for a candidate that wants to pursue MSc program abroad. I've known the candidate since his first year of undergraduate studies and also I included him in some personal projects of mine. However, I wonder how should I address him in the letter. These are the options:


Address him by last name only: 


  Mr. Doe was...

Address him as 'the candidate':


  The candidate's motivation...



Any opinions on which one is preferred?
You are writing on behalf of the applicant, and are supposed to be providing information that shows how well you know the applicant's strengths and weaknesses. That knowledge is more convincingly implied if you refer to the candidate by her name, rather than as "the candidate" or "the applicant."

Also, most good letters of recommendation I've seen actually refer to the candidate by her first name, rather than as "Ms. Doe."