AcceptedDomainsAnalyzer

Exports Exchange Online Accepted Domains configuration and (optionally) runs domain DNS health checks (MX/SPF/DKIM/DMARC/MTA) and exports everything to CSV.

• PowerShell 7 compatible
• Designed for Microsoft 365 consulting / auditing
• Best-effort approach: continues when some checks/cmdlets/modules are not available

Credits

This project is based on the original work by Ernesto Cobos Roqueñí.

Original script inspiration and implementation:

https://github.com/ernestocrmsft/guacamole/blob/main/Scripts/GetAcceptedDomains-HealthChecker.ps1

The original script was adapted and significantly extended to support:

• Exchange Online consulting and audit scenarios
• PowerShell 7 compatibility
• Execution logging and structured output
• PASS / FAIL authentication posture analysis (SPF, DKIM, DMARC)
• Multi-tenant friendly execution

Many thanks for the original idea and implementation.

What it does

• Retrieves Get-AcceptedDomain from Exchange Online
• Optionally performs DNS checks per accepted domain:
  • MX lookup (via Resolve-DnsName when available)
  • SPF / DKIM / DMARC / MTA (via DomainHealthChecker module)
• Exports a single CSV with both configuration and analysis fields

Requirements

• PowerShell 7+
• ExchangeOnlineManagement module (script imports it; can optionally install it)
• Permissions to connect to Exchange Online and run Get-AcceptedDomain
• Optional (for DNS checks): DomainHealthChecker module

Usage

Basic export (no DNS checks)

.\Export-AcceptedDomainsConfig.ps1 -OutputPath .\AcceptedDomains.csv