Update: Solved!
So I've continued to research this and come across the following post:
http://www.iredmail.org/forum/topic1258 … tside.html
I implemented the following changes suggested in the bottom few posts:
I changed two values in /etc/postfix/main.cf
smtp_reject_unlisted_sender = no
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
After restarting the server I am now able to receive e-mail! Wahoo! After a few days of tinkering it's nice to see the tons of test e-mails trickle in. Anyways I was wondering if anyone had the time could they possible explain what I essentially did. At a basic level I understand I turned off restrictions on incoming mail senders. Does this open me to more spam possibilities or any other vulnerabilities? Is there another solution I might have missed?
At the very least I wanted to post that my issue is SOLVED and maybe it will help others with similar issues. As mentioned if anyone has the time to explain what I did and why it worked I'd appreciate it - I'll be looking into it anyways.
Cheers, and thanks to the developers for this really cool tool!