How Do You Install the Microsoft Outlook Plugin? (individual users)

The CalendarHero Outlook Plugin allows you to quickly schedule meetings - all without ever leaving your Outlook inbox. 

NEW! Based on customer feedback, we updated the Outlook Plugin user experience for a faster and more efficient scheduling workflow. Learn more about how to use the Outlook Plugin here

How to Install the Outlook Plugin (Individual Users):

Individual users can install the CalendarHero Outlook Plugin by adding it to their custom Outlook Add-ins. (If you are an administrator and want to install the plugin for your entire organization / several team members at once using the Office 365 admin portal - please view Admin instructions here.)

NOTE: Installing the Outlook plugin requires you to copy a manifest URL. If you are on Microsoft Exchange you will need to download and then upload this manifest file. 

CalendarHero Manifest URL:
  1. To use the Outlook plugin you must first create a CalendarHero account.
  2. If you already have a CalendarHero account open your preferred version of Outlook. If you use multiple versions of Outlook (web and desktop) you will need to install the plugin on each version.
  3. Navigate to the “Add-Ins” menu:
    1. In the new version of Outlook web: 
      1. Add-in management is available under “...” ('More actions' menu which is visible from a selected email) 
      2. Click “Get Add-ins” from the "..." menu
      3. From the “Custom Add-ins” pop-up click the “My Add-ins” tab
      4. On the “My Add-ins” tab scroll down to bottom of the page and click the “+ Add a Custom Add-in link. See Step 4.
    2. In the older version of Outlook web: Add-in management is available under “Settings” > “Manage Add-Ins” >  “Custom Add-ins” > “My Add-ins” > “+ Add a Custom Add-in”
    3. In the Windows Outlook App: Add-in management is available under “File” > “Manage Add-ins” → This opens the Office 365 Manage add-ins (in a browser)> Add from a URL
    4. If you do NOT have access to an "Add-Ins" menu in your version of Outlook please contact your IT Administrator, as this option may need to be enabled.
  4. Once you click “+ Add a Custom Add-in” you will need to paste  the CalendarHero Manifest URL  (or if you are on Exchange please download and then upload this file)
  5. Once your Outlook Plugin is added learn how to access and authenticate

New Web version of Outlook

Outlook on Microsoft Exchange

How to Access & Authenticate the Plugin

Once the plugin is installed, you can easily access it from their Outlook Inbox by clicking the CalendarHero plugin button. Click again to close. Learn more about how to use the Outlook Plugin here

  • OnClick the plugin will open at right (desktop) or full (mobile)
  • The plugin button is also available from the Reply screen (below the reply box)
  • On Mobile (App) the plugin is available under the “…” menu


The first time the plugin is opened, you will see an “Authenticate” button that allows you to authenticate and log in. You can click “Authenticate” to log in with your MS account.

  1. Click on “Authenticate” (Or if you are on Exchange click "Authenticate with Exchange")
  2. Select your Email Access by clicking "Allow Access" or "Don't Allow". (Note: Rest assured CalendarHero NEVER reads the contents of your emails)
  3. Display New window: Next the message “(CalendarHero) Assistant wants to display a new window” appears.
    1. OnClick: Allow opens MS Account login - see 4
  4. MS Account Login: The MS Account login pop-up opens in a new tab/window. Select the account you already used to register with CalendarHero and login.
  5. All done: That’s it! You're now authenticated and can use the CalendarHero Outlook Plugin.

Note: If you registered your CalendarHero account using Exchange you will use the "Authenticate with Exchange" link and login within your Exchange credentials:


If you are experiencing issues adding the plug-in on the Outlook desktop version it could be because of a cache problem. Please try to below process: 

  • Right click inside the plugin
  • Click inspect
  • Go to Application tab
  • On the right, under Storage, right click and click Clear on all

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