What is Exchange ActiveSync (EAS), CalDAV, CardDAV?
Exchange ActiveSync (commonly known as EAS). It is and Add-on feature from ABCHK.com that synchronizes your emails, contacts and calendar between Webmail and your Mobile Devices.
Exchange ActiveSync : Mail, Calendar, Contacts sharing
CalDAV . .: Calendar sharing protocol
CardDAV : Addressbook sharing protocol.
How can I set it up and any fee ?
EAS is an Add-on feature, it charge HK$5/mth/user
. (Order Form) and you can use those features