I'm deploying zimbra into a new office. they only have 1 physical server which they want to use for their mailserver and network/fileserver. for fileserver they want win2k3 setup. for mailserver i want to implement zimbra.

the current setup they have is a win2k3 server, with vmware installed. then 2 linux guest OS's are installed, one for mailserver and one for assp antispam.

would it be better to have linux as the main OS, where zimbra will be installed, then have just guest OS which will be the win2k3 box and it will also be the authentication (active directory) for the lan stations?

the existing setup IMO might be the reason we are having issues with the existing mailserver, which cannot send out email to yahoo and to other major ISPs, although it can receive without problems...i find it easier setting a linux box as a dns server rather than a win2ks box as a dns server....

what are your thoughts on this?