Write your chaser emails as a ladder, not one email you keep re-sending

Most people write one chaser email, and when it doesn't work, they send the same one again with "just following up" bolted onto the top. That's not persistence - to whoever's ignoring it, it reads as proof there's no real consequence to ignoring you, because the second email asked for exactly nothing more than the first one did.

Ask for all three chasers at once, as a tone ladder, before you send the first one. Give the model the request, who it's going to, and how many times you're prepared to chase before escalating, and ask for three versions: friendly reminder, direct follow-up naming the actual deadline impact, and a final one that states plainly what happens next if there's no reply - copying in a manager, missing a hard deadline, whatever's genuinely true for your situation. Each one should read like a real escalation, not just the same email typed louder.

The value isn't really in the wording - it's in having decided your own escalation path in advance, calmly, instead of improvising the tone of email three while already annoyed. You send email one. If it doesn't land, email two is already sitting there ready to go, matched to what you actually meant by "following up" the first time.

One thing to get right up front: the final rung has to name something that's actually true. A closing line that threatens an escalation you have no intention of following through on gets found out the first time someone calls the bluff - and the ladder stops working for every future chaser to that person, not just this one.