diff --git a/Calendar/Get-RBASummary.ps1 b/Calendar/Get-RBASummary.ps1
index e46636ffde..9d63b1f7c1 100644
--- a/Calendar/Get-RBASummary.ps1
+++ b/Calendar/Get-RBASummary.ps1
@@ -55,6 +55,22 @@ function ValidateMailbox {
     Write-Host ;
 }
 
+# Validate that there are not delegate rules that will block RBA functionality
+function ValidateInboxRules {
+    Write-Host "Checking for Delegate Rules that will block RBA functionality..."
+    Write-Host -NoNewline "Running : "; Write-Host -ForegroundColor Cyan "Get-InboxRule -mailbox $Identity -IncludeHidden"
+    $rules = Get-InboxRule -mailbox $Identity -IncludeHidden
+    # Note as far as I can tell "Delegate Rule <GUID>" is not localized.
+    if ($rules.Name -like "Delegate Rule*") {
+        Write-Host -ForegroundColor Red "Error: There is a user style Delegate Rule setup on this resource mailbox. This will block RBA functionality. Please remove the rule via Remove-InboxRule cmdlet and re-run this script."
+        Write-Host -NoNewline "Rule to look into: "
+        Write-Host -ForegroundColor Red  "$($rules.Name -like "Delegate Rule*")"
+        Write-Host -ForegroundColor Red "Exiting script."
+        exit;
+    }
+    Write-Host -ForegroundColor Green "Delegate Rules check passes."
+}
+
 # Retrieve the CalendarProcessing information
 function GetCalendarProcessing {
     Write-Host -NoNewline "Running : "; Write-Host -ForegroundColor Cyan "Get-CalendarProcessing -Identity $Identity"
@@ -476,6 +492,7 @@ function Write-DashLineBoxColor {
 
 # Call the Functions in this order:
 ValidateMailbox
+ValidateInboxRules
 GetCalendarProcessing
 EvaluateCalProcessing
 ProcessingLogic
diff --git a/docs/Calendar/Get-RBASummary.md b/docs/Calendar/Get-RBASummary.md
index 7da1d3c6d5..817a29ea6a 100644
--- a/docs/Calendar/Get-RBASummary.md
+++ b/docs/Calendar/Get-RBASummary.md
@@ -5,7 +5,7 @@ Download the latest release: [Get-RBASummary.ps1](https://github.com/microsoft/C
 
 This script runs the Get-CalendarProcessing cmdlet and returns the output with more details in clear English, highlighting the key settings that affect RBA and some of the common errors in configuration.
 
-The script will validate the mailbox is the correct type for RBA to interact with via the Get-Mailbox cmdlet.
+The script will also validate the mailbox is the correct type for RBA to interact with (via the Get-Mailbox cmdlet) as well as check for any Delegate rules that would interfere with RBA functionality (via the Get-InboxRules cmdlet).
 
 
 Syntax: