I installed Zimbra trial on a fresh Red Hat Enterprise Server 5 install, and everything went swimmingly (or so it seemed).

I can access Admin panel, and send e-mails through webmail.

When I attempt to e-mail the myself at the new server, example@zimbramail.net, from my regular e-mail, example1@original.com, it gives me a
554 5.7.1 "example@zimbramail.net": Relay access denied
(replace "s with <>)

This error goes away when I sent something from the new account to the old account- but I need to be able to receive mail from contacts that I may not have initiated.

Sorry in advance if this is replicated somewhere else, I spent about 30 minutes searching through here, but couldn't find anyone that had this same issue.