OP, that was a rookie mistake. For shame.
I would probably pretend that it never happened. The people who manage that inbox are probably admin people with little decision making power.
What the fuck are they going to do, put in your file "Applicant Duck55 put an emoticon

in message. Strange. (2/12/2015)."
Personally, if I'm a worker in my busy season, I wouldn't take the time to record a barely scrutable message with a high likelihood of having been sent in error. Especially given they are catching up with work due to the snow.