Add message-counter.ps1

message-counter.ps1

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+<#
+.SYNOPSIS
+    Count the number of received emails in a Microsoft 365 mailbox during a specified time window.
+
+.DESCRIPTION
+    This script queries Exchange Online via Microsoft Graph to return the total count of emails
+    received by a specific mailbox within a given date range. It searches all folders in the mailbox
+    (including Inbox, subfolders, Junk, and Deleted Items), ensuring that emails moved after delivery 
+    are still included in the count. Drafts are excluded, and self-sent messages from the mailbox 
+    owner are not counted as "received."
+
+    Date boundaries are applied using local time (Eastern Time in this example). 
+    Adjust offsets (-05:00 / -04:00) for daylight savings or your region.
+
+.PARAMETER $u
+    The target user’s email address. Example: 'f@d.org'
+
+.PARAMETER $start
+    The inclusive start of the time window in ISO 8601 format with time zone offset.
+    Example: '2025-01-01T00:00:00-05:00' for January 1st, 2025, 12:00 AM ET.
+
+.PARAMETER $end
+    The exclusive end of the time window in ISO 8601 format with time zone offset.
+    Example: '2025-02-01T00:00:00-05:00' for February 1st, 2025, 12:00 AM ET.
+
+.OUTPUTS
+    Returns a single integer representing the count of received messages.
+
+.NOTES
+    Requirements:
+      - Microsoft.Graph PowerShell module
+      - Connect-MgGraph with Mail.Read delegated permission (if signed in as the user)
+        OR Mail.Read application permission (with admin consent) if run as a service.
+
+    Example to install module: Install-Module Microsoft.Graph
+    Example to connect:        Connect-MgGraph -Scopes Mail.Read
+
+    (c) 2025 Robbie Ferguson. All rights reserved.
+#>
+
+$u='mailbox@domain.com';$start='2025-01-01T00:00:00-05:00';$end='2025-02-01T00:00:00-05:00';$c=0; Get-MgUserMessage -UserId $u -Filter "receivedDateTime ge $start and receivedDateTime lt $end and isDraft eq false and (from/emailAddress/address ne '$u')" -CountVariable c -ConsistencyLevel eventual -PageSize 1 | Out-Null; $c