The SharePoint Business Data List Connector is used to simply connect a SharePoint list with external LOB data, e.g. from databases, CRM or ERP systems.
SharePoint out-of-the-box can sync some data in Microsoft Exchange to some lists in SharePoint, e.g. events. Connecting a custom SharePoint list to Exchange or Outlook with the Business Data List Connector (BDLC) to pull data into this list is a more general approach. You have to provide a connection string, a select statement and primary key(s) - if any - to connect a custom SharePoint list directly in the list settings dialog using the BDLC.
Please note, that the Microsoft OLEDB Provider for Exchange (ExOLEDB) has some known limitations:
ExOLEDB can only be run on a computer on which Exchange is running, and can only access databases and storage groups that are actually managed by that Exchange server. ExOLEDB can not be used on front-end Exchange servers or client computers.
To access Exchange data via Outlook with the Jet OLEDB provider you can use a connection string like this:
Provider = "Microsoft.JET.OLEDB.4.0;Exchange 4.0" "MAPILEVEL=Mailbox - James Smith|; PROFILE=MS Exchange Settings;TABLETYPE=0;DATABASE=C:\WINDOWS\TEMP\;"
Be sure to replace the mailbox name and the temp path (has nothing to do with the database) as required. You must keep vertical pipe character | to indicate top level of folders. Place sub-folders after vertical pipe if accessing specific folders.
You can use a select statement like this:
"Select * from Calendar" or "Select * from Contacts".
By the way you can connect using a personal Microsoft Office Outlook installation too, if required:
Provider="Microsoft.Jet.OLEDB.4.0;Outlook 9.0;" "MAPILEVEL=;DATABASE=C:\Temp\;"
Please take care, that the current SharePoint user or (in case of using a timer job for background updates) the process user has the appropiate access rights.