Attach files to Outlook emails with the Message attachments button
With the Message attachments button on the Shared Email Templates editor toolbar, you can automatically attach files from OneDrive, SharePoint, and URLs to Outlook emails.
When creating or editing your Outlook email template, click the
Message attachments button on the template editor toolbar.Choose where your file will come from (OneDrive, SharePoint, or a URL) and click the plus sign next to the corresponding option.
Select a file or enter a URL.
Close the Message attachments dialog.
A blue asterisk will appear on the Message attachments button:

Save the template.
When you use the message template, the specified attachments will be automatically added to your Outlook email.
If you’d rather work on your templates in the Shared Email Templates app in your browser, you can also add attachments in a separate field above the template editor toolbar. To display the field, click the Attachments button. Then click the plus sign and choose where to add the attachment from: OneDrive, SharePoint, or URL.

Choose the file you want to attach and click Select, or enter a URL and click Add. Once the attachment is added, a blue asterisk appears on the Attachments button.
To open or remove an attachment you’ve added, open the More menu and select Open or Remove.
