The 2026 checklist
- DMARC enforced, DKIM aligned, SPF clean
- Warmup only for genuinely new domains
- Under 40 cold sends per mailbox per day
- Reply-first metric, opens deprioritized
What to stop
Purchased list blasts. Aggressive warmup that trips ESP heuristics. Multiple burner domains that all look the same.
The strategic shift
Higher-quality lists, lower daily send, better replies. This is the direction of every serious outbound team.