I am very new to Zimbra and have installed it on a Xen virtual machine running CentOS 5.5 for trial. I did not encounter any issues during installation and all services appear to be up and running. I am running Split DNS due to the fact that I am behind a SonicWall firewall with SMTP, IMAP, and POP3 being forwarded to the VM. I was able to create a test account.

The issue that I am running into is that I am neither able to send or receive any messages to any accounts that are either internal to my Zimba installation nor to the outside world. I have verified that outside services are able to access smtp within my network. Are there any basic steps that I can check or what my next step should be with troubleshooting?