Get-TeamsExternalAccessReport

<#
.SYNOPSIS
    Reports Teams external access and federation configuration.

.DESCRIPTION
    Checks tenant level external access settings, whether federation is
    open or restricted, and lists any domain specific allow or block
    entries, so the actual federation posture is confirmed rather than
    assumed.

.EXAMPLE
    .\Get-TeamsExternalAccessReport.ps1

.NOTES
    Requires the MicrosoftTeams module and an active Connect-MicrosoftTeams session.

.AUTHOR
    Shehryar Hassan
#>

$config = Get-CsTenantFederationConfiguration

[pscustomobject]@{
    AllowFederatedUsers      = $config.AllowFederatedUsers
    AllowPublicUsers         = $config.AllowPublicUsers
    AllowTeamsConsumer       = $config.AllowTeamsConsumer
    BlockedDomainCount       = $config.BlockedDomains.Count
    AllowedDomainsRestricted = $config.AllowedDomains.AllowedDomain.Count -gt 0
} | Format-List

if ($config.BlockedDomains.Count -gt 0) {
    Write-Host "Blocked domains:" -ForegroundColor Yellow
    $config.BlockedDomains | Format-Table -AutoSize
}