Auth error on trying to send email

Auth error on trying to send email

I'm trying to send emails through ZOHO and my Ghost blog (hosted on Digital Ocean), but I'm getting the error "535 Authentication Failed. Please check your email settings". 

This is how I'm configuring it:

"mail": {
    "service": "ZOHO",
    "transport": "SMTP",
    "options": {
      "host": "smtp.zoho.com",
      "port": 465,
      "secureConnection": true,
      "auth": {
        "user": "user@customdomain.com",
        "password": "xyz"
      }
    }
  },

I'm creating an app specific password and trying to use it along with my username and this is not working.