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?