Most replies come from follow-ups, not the first message. Automation ensures follow-through without manual tracking.
The metrics that matter#
- Authentication pass rate: share of mail passing SPF, DKIM, and DMARC alignment. Healthy: 99% or higher.
- Spam complaint rate: Gmail enforces at 0.3%; stay under 0.1%.
- Hard bounce rate: under 2%; above 5% triggers platform reviews.
- Inbox placement: above 90% across major providers via seed tests.
- Engagement: click and reply rates by segment; opens are unreliable after Mail Privacy Protection.
Where to read them#
- Google Postmaster Tools for Gmail domain reputation, spam rate, and authentication.
- Microsoft SNDS and JMRP for Outlook.com IP reputation and complaints.
- Your ESP's delivery and bounce reports.
- DMARC aggregate reports for authentication by source.
Improving the numbers#
- Plan 3 to 5 steps over 2 to 3 weeks; diminishing returns set in after step 5.
- Give each step a distinct angle rather than 'just bumping this'.
- Stop the sequence automatically on reply, bounce, or unsubscribe.
- Thread follow-ups as replies for context, but vary subject lines when starting new angles.
- Review reply sentiment weekly and adjust.
Frequently asked questions#
How many follow-ups should a cold sequence have?
Three to five. Most positive replies come by step three; beyond five, complaints rise.