Optional Essay: paper or electronic?

I want to send in my essay to a few CUNY schools. Do I send it electronically or via mail?

If anyone needs help with this, I sent a paper copy of my essay in an envelope. After that, I got an email from CUNY saying if I wanted to send them my essay electronically, I could. I did that too. So if anyone needs answers, I would recommend doing both just to be sure. Good luck!