What are the system requirements for the phone?

T-Mobile G1 phone fully supports OurApp.

What are the system requirements for Exchange Server?

(For administrators) ContactsCalendarSync™ only works with Microsoft Exchange Server 2007. The Exchange Server should have Exchange Web Services enabled and accessible from the Internet. It is preferable, but not necessary, to have Autodiscover service properly configured and available through the Internet.

Does ContactsCalendarSync™ synchronize with Microsoft Exchange Server 2003?

ContactsCalendarSync™ does not currently work with MS Exchange 2003. Exchange 2003 doesn't support Exchange Web Services. However, we are now researching other options, such as WebDAV and others, to make ContactsCalendarSync™ available for Exchange 2003 users in the future.

Does ContactsCalendarSync™ synchronize my Exchange email?

Ask your Exchange Server administrator to give you IMAP access settings for your Exchange account; then setup your IMAP account on your G1.

You can read more on how to setup your IMAP account access on G1 here: http://help.godaddy.com/topic/167/article/4906?isc=pod109.