Hi @John Cook ,
According to your description, you can use Outlook Web App.
Step 1: Add the “Page Viewer” web part on a web part page
- Go to the page you want to add the web part to
- In the ribbon click Edit tab > Insert tab > More Web Parts button
- In the the web part adder select the Media and Content category > Page Viewer web part > Add button
Step 2: View Outlook Web App segments in the web part
- Click open the tool pane in the new Page Viewer web part
- Type an URL like the following
https://db3prd0206.outlook.com/owa/?exsvurl=1&cmd=contents
in the Link text box, where the highlighted part must be your own mailserver - Your inbox is now available on your SharePoint Online page
For more information, please refer to: https://learn.microsoft.com/en-us/archive/blogs/lystavlen/outlook-web-app-in-sharepoint-online
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