Ironically TL;dr. Not sure I got much out of it. Some of my best practices when talking to developers at my company: -Do not leave voice mails. Go see them in person if you can. -If your signature is longer than your short email and/or contains graphics, rethink your signature. -Turn off HTML in your email client. -Expect in-line responses.

The biggest irony of all of this is that I see so many technical recruiters who have massively long signatures with a bunch of graphics.