So, since I recently wiped my ESXi box and installed CentOS 5.3 on it instead, I went with Zimbra for my e-mail solution, with LDAP authentication, and I have to say so far it works amazing… but e-mail push is a feature i’ll be missing on my phone…
I found the solution to be something called Funambol. It is similar to what BES is for Exchange or Notes. It provides a sync interface for end devices into Zimbra, or Exchange, or others. I’ve been spending the weekend configuring Funambol and Zimbra to see each other, and my phone to sync with it.
Here’s the guide i’ve been following: http://wiki.zimbra.com/index.php?title=Open_Source_Mobile_Calendar_and_Contact_Synchronization