Enable email previewing

The Show Preview command allows you to see a preview of email messages (.msg files) uploaded to M365 using:

Messages uploaded using the Upload button or by dragging and dropping from the Windows Explorer cannot be previewed.

For previewing email messages, harmon.ie saves the content of the email in a SharePoint column named MailPreviewData.

The content is compressed and stripped from embedded objects, such as images, excel tables, etc.

To enable the preview of email messages:

The MailPreviewData column must be added to the SharePoint library and to the content type assigned to email messages. There are a few methods to do it:

  • By configuring email header mapping. Read Automatic email header mapping to learn how.
  • Manually:
    1. Create a column called MailPreviewData in the SharePoint library.
    2. Set Column type to Multiple lines of text, with plain text.
    3. Set Allow unlimited length in document libraries to Yes.
    4. Uncheck Add to all content types (recommended).
    5. Uncheck Add to default view, in order to hide the column from the library view (recommended).
    6. Add this column to the content type assigned to email messages.
    7. Select the column from the content type and set This column is to Hidden, to hide the column from the document properties (recommended).