Difference between BIS and BES Plans in Blackberry

BlackBerry Internet Service (BIS):

A BIS contract is a basic BlackBerry specific “data” contract that's purchased with your device from your Telco (ie. O2, Orange, T-Mobile, Three, VodaFone).

The BIS “push email” functionality that arrived in MDaemon 11 allows a BlackBerry device with a BIS contract to receive email periodically from MDaemon.

Only your email is synced - there is no native support for calendar, contact, tasks or notes synchronisation (a third party SyncML client would be required to achieve this) so any changes you make in MDaemon to these data types are not reflected on your BlackBerry device.

Only email on the BlackBerry device that that has arrived since the email account was setup on it will appear.

With a BIS email poll the reconciliation is one-way. Only messages read on your device will be marked as read on your desktop client. Any messages read on your desktop client will still appear as unread on your device. It's therefore time consuming having to manage two out of sync inboxes.

BIS requires inbound IMAP and SMTP access to be available from the Internet to MDaemon meaning you have to open IMAP ports on your firewall to enable this functionality if those ports aren't already open.

BlackBerry Enterprise Server (BES):

Email Synchronisation:

MDaemon 12 onwards includes a built in BlackBerry Enterprise Server and gives true two-way push email to your BlackBerry device using only a BIS “data” contract (a BES “data” plan is NOT required).

Syncing is instant and if you mark an email message as read or move it to another folder on either the device or your email client the change is reflected in both directions. When you initially activate a BlackBerry as a BES device you can specify how much historic email is passed to the device.

Synchronisation of Calendar, Contacts, Tasks and Notes:

BES supports native two-way synchronisation of your calendar, contacts, tasks and notes between your desktop client and your BlackBerry device without the need for a third party SyncML plugin on the handset.

Alternatively, you can also use internet(normal data plan) without BIS & BES plan.
Read how to use internet(normal data plan) without BIS & BES plan.