I have separate boxes for mx records that do all the virus/spam filtering at the gateway. They use alias files to relay to the correct mail store (in this case zimbra). So my email domain is domain.com, but because of my config the only way I have found for the server to receive email is to add a domain of host.domain.com and add an alias to each user of email@example.com on the zimbra box. This is adding an entry to the addressbook for addressbook/ical sync of firstname.lastname@example.org that I would rather not have users see. Does anyone else know of a better work around for this?