For a Grad Trainee position in recruitment you chouldn't need sales experience - it will be more about personality. Unfortunately, due to the length of time you were with your old company ad the length of time ago it was, it won't stand you in good stead - personally I wouldn't mention it as if you do they will almost immediately query why you left - not that you leaving was your fault in the slightest, but recruitment consultants are nothing if not sceptical and may see it as a bad thing (you leaving as quickly as you did). What sort of recent work experience do you have? If none, what degree did you do?