The Breakup Email

The final email in a sequence — the one explicitly stating you'll stop reaching out — is consistently one of the highest-reply-rate messages in outbound, for a specific, understandable reason: it removes the ongoing pressure of an open-ended sales pursuit and replaces it with a low-stakes, easy "no" or, often, a "wait, actually" from someone who'd simply been busy through the earlier touches.

Why it works

Earlier emails    implicitly ask "will you respond to my ongoing
                  pursuit of this deal" — a larger, more effortful
                  ask than it looks like
Breakup email     explicitly states "I'll stop," which reframes the
                  reply as a low-effort, low-commitment "actually,
                  wait" rather than a decision to re-engage with an
                  open-ended sales process

Removing the implicit obligation is what generates the reply — people who were mildly interested but too busy to engage with an ongoing sequence often respond immediately to a message that requires no further ongoing commitment, just a quick "don't go, let's talk."

Writing it honestly, not passive-aggressively