Cannot send emails

I have a question
How I have set up the email ports on the firewall in cyberpanel. it was configured before and i forgot to take notes.
please help me out, I reboot the server because I was having problems sending emails out, I try changing the IP address from 0.0.0.0./0 to my server IP but i don’t know if that’s the properway to do it please help me out

Hello @axiomteck Happy you are here

Where did you change this ? Kindly be more specific