Add Test-SMTPRelay-M365.ps1

Test-SMTPRelay-M365.ps1

@@ -0,0 +1,60 @@
+<#
+.SYNOPSIS
+Test unauthenticated SMTP relay via Microsoft 365 using MX record and IP-based connector.
+
+.DESCRIPTION
+This script sends a test email through Microsoft 365 (Exchange Online) using a connector 
+that allows mail relay based on the sender's IP address. It does not require authentication 
+and is useful for testing printers, scanners, or any other device that cannot use modern SMTP auth.
+
+.AUTHOR
+Generic / Public version (sanitized for open-source use)
+
+.NOTES
+Requires that your public IP is allowed in an Exchange Online connector.
+Use the MX hostname (e.g. yourdomain-nl.mail.protection.outlook.com) as the SMTP endpoint.
+
+# CHANGELOG
+--------------------------------------------------------------------------------
+Date        | Version | Author         | Description
+------------|---------|----------------|------------------------------------------
+2025-07-18  | 1.0.0   | Public / GPT   | Initial release for generic SMTP relay test
+--------------------------------------------------------------------------------
+#>
+
+# Variables (edit to match your domain and connector setup)
+$from = "relay@yourdomain.com"
+$to = "relay@yourdomain.com"
+$smtpServer = "yourdomain-nl.mail.protection.outlook.com"  # Replace with your actual MX record
+$smtpPort = 25
+$subject = "SMTP Relay Test via Microsoft 365 Connector"
+$body = "This message was sent without authentication using an IP-allowed connector."
+
+# Create email message
+$message = New-Object system.net.mail.mailmessage
+$message.From = $from
+$message.To.Add($to)
+$message.Subject = $subject
+$message.Body = $body
+$message.IsBodyHtml = $false
+
+# Configure SMTP client (unauthenticated, no TLS)
+$smtp = New-Object Net.Mail.SmtpClient($smtpServer, $smtpPort)
+$smtp.EnableSsl = $false
+$smtp.DeliveryMethod = "Network"
+$smtp.UseDefaultCredentials = $true
+
+Write-Host "⏳ Attempting SMTP relay via $smtpServer..."
+
+try {
+    $smtp.Send($message)
+    Write-Host "`n✅ Message successfully sent via connector."
+}
+catch {
+    Write-Host "`n❌ Failed to send mail:"
+    Write-Host $_.Exception.Message
+    if ($_.Exception.InnerException) {
+        Write-Host "`nDetails:"
+        Write-Host $_.Exception.InnerException.Message
+    }
+}