Set-AvailabilityConfig in Powershell: All You Need To Know

Managing free/busy information across your organization can be complex, especially when dealing with cross-forest environments or external tenants.

The Set-AvailabilityConfig cmdlet in PowerShell addresses this challenge.

Whether configuring user-specific access, setting up organization-wide proxies, or controlling external tenants' access to availability data, this cmdlet offers flexibility.

Learn how to use Set-AvailabilityConfig in five easy steps!

What is Set-AvailabilityConfig Cmdlet in PowerShell?

The Set-AvailabilityConfig cmdlet in ExchangePowerShell is a command used to configure access levels for free/busy information within an organization. It allows administrators to define specific accounts or security groups, either on a per-user or organization-wide basis, that are trusted for availability proxy requests.

Below is the syntax of Set-AvailabilityConfig:

3 Things You Can Do with the Set-AvailabilityConfig Cmdlet

Using this command becomes simpler once you understand its parameters. Here are three tasks you can perform using Set-AvailabilityConfig in PowerShell:

1. Control Free/Busy Sharing with Specific Tenants: In Exchange Online, you can use the AllowedTenantIds parameter to specify which Microsoft 365 tenants can access your organization’s free/busy information. This parameter is useful for secure collaboration between trusted organizations.
2. Set an Organization-Wide Proxy Account: With the OrgWideAccount parameter, administrators can designate an account or security group to handle free/busy proxy requests across the entire organization. This is particularly valuable for managing availability in environments with multiple Exchange forests that are not inherently trusted.
3. Configure Per-User Free/Busy Access: The PerUserAccount parameter allows you to define individual accounts or groups that can issue proxy availability service requests on a per-user basis. This gives granular control over who can access free/busy data, enhancing security and flexibility.

Prerequisites for Using the Set-AvailabilityConfig Cmdlet

In order to use this command, you need to comply with these simple prerequisites:

• Permissions Assigned: Ensure you have the required permissions to run the cmdlet. The specific permissions depend on the environment (on-premises Exchange or Exchange Online).
• Exchange Environment: Confirm whether you're working in on-premises Exchange or Exchange Online, as some parameters are exclusive to Exchange Online.
• Trusted Accounts or Groups: Identify the accounts or security groups you want to configure for organization-wide or per-user free/busy proxy access. These can be mailbox users, mail users, or security groups.
• Tenant IDs for Exchange Online: If configuring free/busy sharing in Exchange Online, you need the tenant ID(s) of the organizations you want to allow access to.

5-Step Guide to Using the Set-AvailabilityConfig Cmdlet

Follow these five steps to use this command effectively.

Step 1: Connect to Exchange Online PowerShell

Before you can execute the Set-AvailabilityConfig cmdlet, you need to establish a connection with Exchange Online using PowerShell.

To do this, use the Connect-ExchangeOnline cmdlet:

This command prompts you to enter the credentials of an admin user. Once the connection is successful, you’ll be ready to run commands that interact with your Exchange environment.

Step 2: Understanding the Parameters for Set-AvailabilityConfig

As we mentioned before, the Set-AvailabilityConfig cmdlet is used to manage and control access to free/busy information within your organization.

To use this cmdlet effectively, you need to understand its most important parameters:

• PerUserAccount: This parameter is used when you need to assign a user or security group to manage free/busy information on a per-user basis. For example, if you want a specific user to handle free/busy data for other users, this is the parameter you’ll use.
• OrgWideAccount: This parameter is used when you want to set up an organization-wide free/busy proxy account. It’s generally used for administrative purposes, especially in cross-forest or large-scale environments.
• AllowedTenantIds: This is an Exchange Online-specific parameter. It allows you to restrict which external Microsoft 365 tenants can access your organization’s free/busy data. It’s useful if you want to control or limit the sharing of availability data with external organizations.

Understanding these parameters allows you to control how free/busy information is shared internally and externally, and determine who can access this data.

Step 3: Set Up a Per-User Free/Busy Proxy Account

The PerUserAccount parameter allows you to assign a specific user or security group as the responsible party for handling free/busy information on a per-user basis.

Let’s say you want to assign the user james@meetingroom365.com as the per-user proxy for handling free/busy information. To do that, run this command:

This command configures james@meetingroom365.com as the account authorized to access free/busy information for specified users or those within the same organization.

Step 4: Configure an Organization-Wide Free/Busy Proxy Account

If you need to configure an account or group that has access to free/busy information for the entire organization, you can use the OrgWideAccount parameter.

Now, let’s assume you want to set james@meetingroom365.com as the organization-wide proxy for free/busy information:

This command sets james@meetingroom365.com as the account with permission to access all users' free/busy data across the entire organization.

Step 5: Restrict Free/Busy Sharing to Specific Tenants (Exchange Online Only)

In Exchange Online, you can control which external tenants are allowed to access your organization’s free/busy information by using the AllowedTenantIds parameter.

To allow access to your free/busy data for specific external tenants, use the following command:

This command allows only the tenant with the ID "b7d1a8a3-0735-49f9-a598-45b3c7421253" to access free/busy information from your organization.

You can specify multiple tenants by separating their tenant IDs with commas, which provides flexibility in sharing availability data.

Optimizing Set-AvailabilityConfig for Your Exchange Setup

By effectively using the Set-AvailabilityConfig command, you ensure that internal and external users have the appropriate access to availability information, whether it's for specific users or organization-wide configurations.

Here’s a recap of the key points discussed:

• Set-AvailabilityConfig works to set per-user or organization-wide accounts to manage free/busy data sharing within your Exchange environment.
• With the command, you can control which external tenants can view your availability data using tenant IDs, ensuring security and privacy.
• If the cmdlet isn’t working, check permissions and ensure you're connected to Exchange PowerShell, as missing permissions or connection problems are common causes of failure.