Email Attachment of WebFile

The docs tell me to use EmailAttachment.LoadFromFile to attach an existing file to an existing EmailMessage. I’d like that EmailAttachment to be a WebFile that I create with code using MBS DynaPDF. Do I really need to save that file to the server’s hard drive before attaching it, using EmailAttachment.LoadFile? I was hoping to somehow directly attach the WebFile to the EmailMessage. But LoadFile uses FolderItem.

I found my answer here: