Wanna send multiple emails to new question, answers and comments.

Hi Everyone. Hope you are doing great.
I want to send multiple mails to register users for for question, answers and comments. I have added one mail in a field given at the bottom of questions> setting > email page. But when I add more than one emails, it does not send to second one and next to them. Please help me how to add multiple emails. So I can send emails to all users.