Great copy cannot save an email that never reaches the inbox. Run this checklist before you scale sending.
Authenticate everything
- SPF, DKIM, and DMARC on every sending domain.
- Use a subdomain for cold outreach, never your primary domain.
Warm up gradually
Ramp volume over weeks, not days. Sudden spikes are the fastest way to a spam folder.
Avoid fake warmup networks. Mailbox providers detect them, and the short-term boost is not worth the long-term reputation hit.
Watch the signals
| Signal | Healthy range |
|---|---|
| Bounce rate | Under 3 percent |
| Spam complaints | Under 0.1 percent |