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Cleaning Meetings in M365
Microsoft 365, Exchange16. September 2026

Cleaning Meetings in M365

Drago Petrovic

Drago Petrovic

Microsoft MVP

This documentation describes how to properly cancel and remove meetings and recurring meetings organized by a departed employee from the calendars of all attendees and resource calendars (e.g., conference rooms) in Microsoft 365.

Important Prerequisite: The departed employee's mailbox must not be permanently deleted yet. Execute these steps as part of the offboarding process, before the account is completely removed from Microsoft 365.

Method 1: The Best Practice Approach (PowerShell)

This is the official and most efficient method. It automatically sends cancellations to all attendees and frees up previously booked rooms.

Step 1: Check Prerequisites & Install Module

Launch PowerShell as an Administrator. If you haven't already, you need to install the Exchange Online module:

Install-Module -Name ExchangeOnlineManagement -Force
Step 2: Connect to Exchange Online

Log in with your Administrator account (Global Admin or Exchange Admin):

Connect-ExchangeOnline -UserPrincipalName [email protected]
Step 3: Delete Meetings (Remove-CalendarEvents)

Use the Remove-CalendarEvents cmdlet to cancel the meetings. Here are two typical use cases:

Use Case A: Standard Cleanup (1 Year)

Employee John Doe is leaving the company. All of his future meetings for the upcoming year should be canceled.

Remove-CalendarEvents -Identity "[email protected]" -CancelOrganizedMeetings -QueryWindowInDays 365

Use Case B: Preview Affected Meetings (WhatIf)

If you are unsure and want to see which meetings would be deleted without actually executing the command, use the -WhatIf switch:

Remove-CalendarEvents -Identity "[email protected]" -CancelOrganizedMeetings -QueryWindowInDays 120 -WhatIf
Step 4: Disconnect Session

For security reasons, always disconnect your session after successfully completing your tasks:

Disconnect-ExchangeOnline -Confirm:$false

Method 2: The Manual Workaround (Web Interface / GUI)

Use this method only if you lack PowerShell permissions or if you need to manually manage a specific, single recurring meeting.

Step 1: Convert to a Shared Mailbox
  • Open the Microsoft 365 admin center.
  • Go to Users > Active users.
  • Click on the departed employee's name.
  • Select the Mail tab and click on Convert to shared mailbox.
Step 2: Grant Full Access Permissions
  • Scroll down in the user's Mail settings to Mailbox permissions.
  • Click on Manage mailbox permissions.
  • Add your own Admin account under Read and manage (Full Access).
Note: It can take up to 60 minutes for the permissions to fully synchronize across the cloud.
Step 3: Open Mailbox and Cancel the Series
  • Open Outlook on the web (OWA) with your Admin account.
  • Click on your profile picture in the top right corner and select Open another mailbox...
  • Enter the email address of the departed employee and open it.
  • Switch to the Calendar view.
  • Locate the recurring meeting in question.
  • Right-click it and select Cancel -> Cancel series.
  • Send the cancellation. The meeting will now be removed from all attendees' calendars.