I installed the Zimbra desktop. The only error I saw during the installation was something about not all Zimlets were installed.

Now I am trying to setup a POP mail account. When it comes time for the SMTP setting, and I do the validate and save, I get the error "service.FAILURE: system failure: SMTP connect failure". The settings are exactly the same as my current email client (Cox Communications is my internet provider). My regular email works fine. Why the problem here?