RemixIconEx.Business.mail_unread

You're seeing just the function mail_unread, go back to RemixIconEx.Business module for more information.
Link to this function

mail_unread(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Business.mail_unread()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M16.1 3a5.023 5.023 0 0 0 0 2H4.511l7.55 6.662 5.049-4.52c.426.527.958.966 1.563 1.285l-6.601 5.911L4 7.216V19h16V8.9a5.023 5.023 0 0 0 2 0V20a1 1 0 0 1-1 1H3a1 1 0 0 1-1-1V4a1 1 0 0 1 1-1h13.1zM21 7a3 3 0 1 1 0-6 3 3 0 0 1 0 6z" />
</svg>

example usage

svg.icon {
  width: 96;
  height: 96;
}