I am new to Zimbra and I am very interested in using this software.
I have dedciated servers in hosting that I use but my testing server is at home,
I have a business class cable connection and I am allowed to run servers. the only problem is my isp blocks outgoing port 25.

Is there a way to setup Zimbra as a mail server/client but all outgoing email would go threw my isp's outgoing mail server instead of having my own outgoing mail server?

I am a bit new to email servers but I am not new to linux/unix.

Thank you very much for any tips/hints/solutions