Adding social media icons to email signature apple mail with url or SVG, not by attachment
So, to my knowledge SVG isn't possible in HTML email. As I understand it you have to create a placeholder signature and then find the .mailsignature file in your system. This will be in the iCloud folder on more recent systems and in the Library folder on older systems. From there you should be able to replace the &lt;body&gt;&lt;/body&gt; tags in the signature file leave the header as is. The process is a little more complex, as you'll have to make sure your signatures aren't using the default font and that you configure your text editor to open as unformatted HTML. There's nuances to the process, but there should be no reason you couldn't use an URL for an image. They will get treated as attachments unfortunately regardless of how you add it I believe, and you can't really do much about how the signature looks past the first time it is delivered. Good luck and I hope this helps.