When you select account type == gmail, I'm assuming that Zimbra Desktop is using IMAP and not POP to connect to gmail.
However, there appears to be a pretty significant delay in receiving messages. I receive them much quicker on my cellphone (almost instantly) and it takes 2-3 minutes or longer on desktop.
In addition, is there a way to make zimbra push changes back to gmail quicker? I.E. when deleting messages or moving to folders?