This may be user error but I can't figure out how to insert a picture into my signature. I'd like to include my company's logo. There is an "Insert Images" button when you create an HTML signature, and I tried using a URL like this:

file:///c:/logo.jpg

but all this did was include this URL in the signature, not embed my company's logo. I also tried to drag and drop the logo file onto the signature edit window, but that seemed to give weird results, and didn't always even work. At best I got a picture frame outline but no picture inside the outline.

So, can this be done?