Hi, i’m a little bit confused, i have openproject v7.4.2 installed on linux ubuntu 16.04 lts, openproject works fine but when i write smtp server parameters i try to send email test but i got this message:

An error occurred while sending email (503 5.5.1 Error:Authentication not enabled)

my question is this:
i have installed openproject in 1 server and i have my server smtp external, do i need install anything else like postfix or other to make it work?

i hope you can help me guys, thanks.