Hestia SMTP additional IP

Hi,

I have a hestia instance with 2x public IP. I wanna use 1 IP for the WEB part for my websites, and another IP for the mail. If my domain.com have IP one, can I use IP two for the same domain mail server, or I need to change domain.com WEB to the IP two, for the same IP to be used for that domain mail server?