To include the SVG file in your supplier/manufacturer email please follow these instructions.
Navigate to Sign Customiser admin on your store.
Click on "Customisers" in the home menu
Click on the customiser you wish to edit
Click on "Manufacturer Email" in the lefthand side menu
Paste the following code into the email template to display an SVG download link in the email:
<b>SVG:</b> <a href="##{{{ svgPreviewLink }}}" target="_blank">Link</a><br>
This is what the email template should look like after you after you have pasted the code.
Here is an example of the Manufacturer email with an SVG download link.