login to 2 different mailbox server

[Umarzuki Mochlis]

i want to be able to SSO via a public name (e.g.: mail.domain.com) to
2 different mailbox server (Zimbra). Both with its own openldap.

reason is because zimbra proxy only works on Network edition but
another mailbox server is open source version so I had to find another
way for both Network and Open Source mailbox users able to log in on
same address/URL

thanks for any suggestion/idea.

-- 
Regards,

Umarzuki Mochlis
http://debmal.my