The following describes a scenario and resolution which I recently resolved. The AffectedListName was a Mail-Enabled Security Group which was not able to be found in the GAL on any client using Cached-Exchange Mode.
Our scenario was caused by a existing group being renamed but the SMTP address not being changed.
I am using the following variables which you will need to change to suit your environment:
AdministrativeGroupName
MailboxServerName
AffectedListName
AffectedListOldName
Company.com
Enable Diagnostic Logging:
Using Exchange System Manager -> Administrative Groups -> AdministrativeGroupName -> Servers -> MailboxServerName
Right-click and Properties of MailboxServerName.
Diagnostics Logging Tab
Service MSExchangeSA
Category OAL Generator
Logging Level Maximum
Enable Full Download of OAB if Differential Fails:
Create REG_DWORD named “OAL post full if diff fails” at the following location
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeSA\Parameters\
Set Value to 1 to enable 0 to disable. Do not leave enabled long term. No service restart is necessary.
Rebuild Recipient Update Services for All Scopes (this varies based on the number of domains):
Using Exchange System Manager -> Recipients -> Recipient Update Services
Right-click and Rebuild on all items.
Rebuild Default Offline Address List:
Using Exchange System Manager -> Recipients -> Offline Address Lists
Right-click and Rebuild on Default Offline Address List.
Monitor Application Log on MailboxServerName:
Open Event Viewer and watch for Warning and Error Events
I was receiving a warning entry indicating:
OALGen skipped some entries in the offline address list '\Global Address List'. To see which entries are affected, event logging for the OAL Generator must be set to at least medium.
This event was Event ID 9327 Source MSExchangeSA Category OAL Generator
I was receiving an error entry indicating:
OALGen will skip user entry 'AffectedListName' in address list '\Global Address List' because the SMTP address '' is invalid.
This event was Event ID 9325 Source MSExchangeSA Category OAL Generator
Correct SMTP Address on Entry:
Using Exchange Active Directory Users and Computers find the object in question
Right-click and properties.
Email Address Tab
The Primary SMTP address was AffectedListOldName@Company.com – Which conflicted with the Recipient Policy. I updated it appropriately and was able to regenerate the Default Offline Address List.
Rebuild Default Offline Address List:
Using Exchange System Manager -> Recipients -> Offline Address Lists
Right-click and Rebuild on Default Offline Address List.
Monitor Application Log on MailboxServerName:
Open Event Viewer and watch for Warning and Error Events
You should not receive any errors or warnings if everything worked. The following entry will confirm proper resolution.
I received an information entry indicating:
Offline address list generation finished.
This event was Event ID 9107 Source MSExchangeSA Category OAL Generator
Confirm Resolution:
Cache-mode enabled client can “Download Address Book” (via Send/Receive) and see the updated entry in the GAL.
Post-Mortem Tasks:
Disable Diagnostic Logging
Disable Full Download of OAB
Analysis (Why This Happens):
When using Cached Exchange Mode, the Exchange Server allows the client to download a subset of Address Lists to the local hard disk. This allows the Address Lists to be available when the user is not online. When Cached Exchange Mode is disabled the client directly accesses the Address Lists off of the Server. During processing of the Offline Address Lists entries are verified against the Recipient Policies and errors result in the entry being skipped in the OAB. This is a very common issue that most often is ignored, but actually has a very low bar for resolution, once you iron out the process.