Hi, it's possible use only the webinterface, and MY servers ?

I have the servers separated and working in production LDAP, Squid, Samba, Sendmail+Dovecot, and i can use the existing servers with zimbra and not use the servers of zimbra.

What modifications in my servers is necessary to make the webinterface ( ajax webmail, agenda, etc ) work with my existing servers ?

Thanks and sorry about my poor english ( i am brazilian )