Hello all, I followed this guide: http://www.howtoforge.com/perfect-server-ubuntu-10.04-lucid-lynx-ispconfig-3 All incoming mail worked perfect. I could send mail internally. When trying to send mail externally, i would get rejected from other mail servers. What ended up being the problem is my IP was on a block list here: http://www.spamhaus.org/ under the PBL (policy block list). Reason being i am testing building a mail server on a dynamic address at home. upon requested my IP was removed and about 30 min later things started to work. Reason i thought to mention this here is that this is the only issue i had with the install and saw no reference to it anywhere. I hope this can possibly help you too.
I agree 100% but like i said its a test build and i am working at home. You cant learn if you don't try right?
My home server is on a dynamic IP as well. As the IP belongs to RoadRunner the blacklists will not remove it. I tried once and it triggered RoadRunner to change my IP. Other than that it never changes even though it's technically dynamic. The work around for the email is to relay thru a data center server which is not on the dynamic IP blacklists. I used to do this via a rented shared host account. Now I do it through my own servers.
Another workaround is just to use your own ISP's SMTP servers as this article shows http://www.tech-avenue.net/tutorials/isp-as-your-free-open-relay/