Public Folders & Shared ResourcesAddress Book Policies & OAB

Address Book Policies & OAB

20 mins

Understanding the Concept

Address Book Policies (ABPs) create virtual organizations within Exchange Online by controlling which recipients users can see in the Global Address List. This is useful for multi-tenant hosting, mergers, and organizational separation.

The Offline Address Book (OAB) provides a downloadable copy of the address list for Outlook desktop clients, enabling address lookups when disconnected from the network.

ABPs combine a Global Address List, Address Lists, Room Lists, and an OAB into a single policy that can be assigned to mailboxes, creating a segmented directory experience.

Key Points

•ABPs create virtual directory separation within a single organization

•Each ABP includes GAL, Address Lists, Room List, and OAB

•ABPs are assigned per mailbox using Set-Mailbox cmdlet

•OAB provides offline address lookup for Outlook desktop

•Address list filters use recipient properties for membership

•ABPs do not provide security isolation, only visibility control

Why This Matters

Organizations with multiple business units, acquired companies, or hosting scenarios need directory segmentation. ABPs provide a clean separation of address lists without requiring separate Exchange organizations.

Common Mistakes to Avoid

✗Assuming ABPs provide security isolation (they only control visibility)

✗Not creating all four components (GAL, AL, Room List, OAB) before creating ABP

✗Forgetting to assign ABP to mailboxes after creation

Interview Discussion Points

💡Explain when and why you would implement Address Book Policies

💡Describe the components required for an ABP

💡Discuss the security limitations of ABPs

MS-203 Exam Tips

📝Know all four components required for an Address Book Policy

📝Understand that ABPs are visibility-only, not security boundaries

📝Be familiar with PowerShell commands for creating and assigning ABPs

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