<aside> 🔥
Inbox providers don't trust volume they haven't seen before. Whether you're setting up a new sending domain, moving ESPs, or reactivating a list that's gone quiet, you have to earn trust gradually — ramp too fast and you get throttled or sent straight to spam.
</aside>
| Situation | What needs warming |
|---|---|
| New sending domain / new ESP | The domain itself has no sending history — inbox providers have zero reputation data on it |
| Reactivating a dormant or unengaged list | The relationship with subscribers has gone cold — sudden volume to people who forgot they signed up reads as spam |
You don't need to re-warm a domain that's already established and sending consistently — warming is only required when reputation is new or has gone stale.
The principle: start small, send only to your most engaged people, and increase volume gradually so inbox providers can build a positive reputation picture of you before you're sending at full scale.
A typical 4-week schedule:
| Week | Daily volume | Audience |
|---|---|---|
| Week 1 | ~50-100 emails/day | Most engaged subscribers only (opened/clicked in last 30 days) |
| Week 2 | Double week 1's volume | Still engaged-only, slightly widen the window |
| Week 3 | Double again | Begin including moderately engaged (60-90 day) subscribers |
| Week 4+ | Ramp to full sending volume | Full list, but keep unengaged/sunset candidates excluded |
<aside> 🛠️
Klaviyo and most modern ESPs will auto-manage this for you when you connect a new branded sending domain — but the underlying principle matters even if the platform handles the mechanics, because your list quality still determines how fast reputation builds.
</aside>
Rules while warming: