Letter writer (13)
I believe the answer is:
correspondent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">letter writer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for correspondent that I've seen before include "Overseas journalist" , "Person sending letters or written reports - agreeing" , "Journalist; letter-writer" , "Journalist; pen pal" , "Journalist; letter writer" .)