Free tool
The warmup tax
Warming is not a one-time setup cost. Domains burn, and every replacement starts the 51-day clock again. Change any input; the formula is printed underneath.
More than half your annual sending capacity goes on getting domains ready rather than reaching prospects.
inbox-days lost per year 6,120
emails not sent 91,800
replacements per inbox per year 4.0
inboxes × (12 ÷ cycle) × days to ready = inbox-days lost · ÷ (inboxes × 365) = share of capacity
Assumes an inbox not yet ready carries no cold volume. Partial ramping makes the real figure lower and the shape identical.
Or start at day 51
Somebody has to run those 51 days. Prewarmed inboxes arrive on a domain that already has, which is the entire product.
Get inboxesOrders are placed on Warm Inboxes, run by the same team as this site.