Well, not so much “how to follow up” as “how to AVOID following up”. That’s the key.
Your aim is to get us to respond of our own accord, and the secret to that is all in your phrasing.
We’re talking mass mail-outs here, by the way, not tailored emails, so first off I would implore you: do you really, REALLY need a reply? Can you not just trust in technology and assume we got the press release and found it every bit as boring as you, in your heart of hearts, know it to be?
Rule one: be very clear that you expect a response.
Don’t write something bland like “I look forward to hearing your thoughts”, which is just so much white noise. Don’t write “Do let me know if this works for you” because it doesn’t, so we won’t. Be more direct: “Please let me know one way or the other if this works for you.” And put it at the start of your message, because we seldom read to the end.
Rule two: Try the good-cop-bad-cop interrogation gambit. You know the one, where Ted Hastings or whoever says, “Come on big fella, we all know where this is going so why don’t you just give us what we need and make it easy on yourself.” Make clear you’ll bug the hell out of us until we reply. “If you don’t mind, I will follow up in a couple of days to gauge your interest.” That should do it.
Or better still, humanise it. Write “I’m really sorry but my boss is a b*****d who’s going to insist I follow up, so I’d really appreciate you replying.”
I’ll respond to the former because I want an easy life. I’ll respond to the latter because, well, who hasn’t had a b*****d boss.