Kopano Mail Server + NAS on single external IP

Good Morning ,
I only have one fixed external IP Adress available. I need to run my synology NAS port 80 and 443 and also my kopano mail server on the same external IP. I have a pfsense or monowall firewall available. Can I direct all traffic to my mail server (use it as a front end) and then redirect traffic for my NAS to the NAS? and also have a webserver running on the frontend (the mail server)

Thanks for some tips