Hi ,
I'm new to this thing. I 've to set up SMTP server to send outgoing mail for my company. i've tried to setup SMTP server that came with Widows 200 server but i've got
an error message :
550 Unable to relay for customer@mail.com
so I think this 's because firewall has blocked it.

what 're the ports both incoming and outgoing needed to be open ? and could you give me a link to really good tutorials of how to set up SMTP server .

thanks for helping.