Hi @Chene ,
Welcome to our forum!
Agree with AndyDavid, emails in the Reading Pane will only be previewed. Of course, you can also make a variety of settings for your reading pane. For more information about Reading Pane, please refer to: Use and configure the Reading Pane to preview messages.
If you still do not believe that the reading pane will not run active content, use Outlook's read as plain text option via File > Options > Trust Center > Email Security > Read as Plain Text(as shown in the below figure). It's safe to convert all messages to plain text. With one click in the message bar, you can easily revert to HTML format to read any message in HTML format.
Hope the above help!
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