Mail server postfix relay

Greetings,
I just setup postfix email server and i can send and receive emails from my vultr instance. Anyone have any luck setting up postfix to be used as a relay. Is this something that is blocked from vultr or configurable ?
Id like to send emails from another server and send it through postfix
Thoughts?
Thanks

Vultr always block the email ports first you need to confirm that if ports are opened