Thanks guys. I've taken a look at the documents that have been linked. So, right now I'm trying to figure out why I can't send mail. We've setup DNS through Free DNS, Static DNS, Dynamic DNS, URL Redirection, and more from EveryDNS! The thing is though, when going through the documentation you linked, I took a look at the /var/logs/zimbra.log and found the following error:
After, I checked to see if there was an MX record, and there wasn't. We've created an MX record on our DNS, which done through Free DNS, Static DNS, Dynamic DNS, URL Redirection, and more from EveryDNS! Now, I'm wondering if I'm suppose to make an MX record on the server side, or point to the MX record that is stored on our online DNS?
Jul 14 10:37:00 mail2 postfix/postqueue: fatal: Queue report unavailable - mail system is down
root@zimbra:~# host -t mx mail2.pdadmin.com
mail2.pdadmin.com has no MX record
When trying to send an email from one account to another, this pops up: