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.