Improving reply rate without hurting deliverability

1. Narrow the audience. A smaller, better-targeted list beats a bigger one on every metric including deliverability.
2. Shorten the first email. Under a hundred words, one idea, one question.
3. Use one link at most in the first email, or none.
4. Make the personalization specific enough that it could not be sent to anyone else.
5. Ask something easy to answer instead of asking for a meeting immediately.
6. Fewer follow-ups, better spaced. Five aggressive chases generate complaints, not replies.
7. Send at a sane local hour in the recipient's timezone.

Important notes

Engagement and deliverability move together. Anything that makes the email more worth answering also makes it more likely to reach the inbox.