I would like to migrate the existing setup of Win2K + Mdaemon 7.61 with anti-virus (our setup/configuration @ present with 250 mail boxes) to zimbra+clamav+amavis/amavisd-new on Centos4.1 (RHEL 4 based distro..).

MY initial thought was postfix + Courier-Imap + dovecot + maildrop + openldap + sasl2 + mysql + clamav + spamassassin + amavisd-new / mailscanner + Pyzor + Razor + DCC + open exchange which after seeing Zimbra has changed. I would like to integrate my e-mail users using mozilla thunderbird to zimbra intgrated with spamassassin,clamav(amavisd-new) where they can utilize the shared calendrs, global addressbook, etc

Is It possible?