I recently fixed an issue where the Default Offline Address List was on Exchange 2003, deleted and then recreated in Exchange 2007. In Exchange 2003 all Address lists create links in the active directory and in the public folder information stores under the System Folders | OFFLINE ADDRESS BOOK | /o=Organization/cn=addrlists/cn=oabs/cn=Default Offline Address List.

When you delete an address list what you are doing is removing all references from that address list and the following things will happen:

1. The address list association on the private mailbox stores will be removed. This is the msExchUseOAB attribute that is stamped on the mailbox object. If this becomes blank clients will fail to download the OAB and receive the following error: 0X8004010F.
2. If you have a public folder store references to that OAB in the PF store might or might not get cleaned up based on how you have your mixed organization configured.
3. When you try to generate your newly created OAB, the OAB generation will fail with the following errors:

Event Type:    Error
Event Source:    MSExchangeSA
Event Category:    OAL Generator
Event ID:    9369
Date:        12/17/2008
Time:        12:03:00 PM
User:        N/A
Computer:    OABGen
Description:
OALGen encountered an error while publishing the OAB files to the distribution point 'Default Offline Address List'. Check other logged events to see more information about the problem. - Default Offline Address List

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Event Type:    Error
Event Source:    MSExchangeSA
Event Category:    OAL Generator
Event ID:    9328
Date:        12/17/2008
Time:        12:03:00 PM
User:        N/A
Computer:    OABGen
Description:
OALGen encountered file error ffffffff (internal ID 505026d) while generating the offline address list for address list '\Global Address List'.  Make sure there is enough disk space available. - Default Offline Address List

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Event Type:    Error
Event Source:    MSExchangeSA
Event Category:    OAL Generator
Event ID:    9328
Date:        12/17/2008
Time:        12:03:00 PM
User:        N/A
Computer:    OABGen
Description:
OALGen encountered file error ffffffff (internal ID 5050236) while generating the offline address list for address list '\Global Address List'.  Make sure there is enough disk space available. - Default Offline Address List

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

The Problem

When you recreate that address list we are re-establishing the links to the objects that were previously deleted. When you try to rebuild the address list you can actually see in the application log that we make a connection to the public folder store even know the newly created address list has only be configured for Web Distribution:

Event Type:    Information
Event Source:    MSExchangeSA
Event Category:    OAL Generator
Event ID:    9134
Date:        12/17/2008
Time:        12:26:38 PM
User:        N/A
Computer:    OABGen
Description:
OALGen successfully created or opened the sub folder 'OAB Version 4' under the offline address list folder '/o=Organization/cn=addrlists/cn=oabs/cn=Default Offline Address List'.
- Default Offline Address List

From here we will try to create our distribution point, however we will fail because the old OAB was never configured this way.

How to fix

1. Create your new Offline Address List (the one that is failing).

2. Only configure it for 'Public Folder Distribution'.

3. Rebuild your Offline Address List - you should see this complete with a 9107 event.

4. Go back and reconfigure your OAB for 'Web Distribution'.

5. Rebuild your Offline Address List - you should see this complete with a 9107 event.

6. Check your (CAS) Client Access Server for the 'General' 1008 event to make sure that the OAB files were copied over.

and that is it!

Dave