True. I'm lazy too
The default settings should be something like /24 - .1 & .254
Or even better, Zimbra should ask what the firewall address is.
I don't agree, those are setting that an Admin should check and see what's neede before installing any package. If you've got a spammer on your network then there's nothing going to stop them from spamming, at some point you have to allow them to email through your server. I could ask, why didn't you know your software was going to do this before you installed Zimbra?