Define the custom ViewHolder for our emails list.

EmailViewHolder.java

public class EmailViewHolder extends RecyclerView.ViewHolder{

    private final TextView textViewFrom, textViewSubject, textViewBody;
    private final LinearLayout linearLayoutEmail;

    public EmailViewHolder(@NonNull View itemView) {
        super(itemView);

        textViewFrom = itemView.findViewById(R.id.textViewFrom);
        textViewSubject = itemView.findViewById(R.id.textViewSubject);
        textViewBody = itemView.findViewById(R.id.textViewBody);
        linearLayoutEmail = itemView.findViewById(R.id.linearLayoutEmail);
    }

    public TextView getTextViewFrom() {
        return textViewFrom;
    }

    public TextView getTextViewSubject() {
        return textViewSubject;
    }

    public TextView getTextViewBody() {
        return textViewBody;
    }

    public LinearLayout getLinearLayoutEmail() {
        return linearLayoutEmail;
    }
}