Warmup only works when the system can see where its emails actually land. We fixed an issue where placement detection — the mechanism that tells warmup whether a test email reached the inbox or got filtered into spam — was unreliable across some mail providers. Without that signal, your sender score could stall even when your sending was healthy, and spam rescue had nothing reliable to act on.
What was happening
Warmup works by sending controlled test emails between a network of trusted accounts and reading the result. The placement signal — inbox or spam — is the core input the system uses to decide whether to increase your daily send volume or hold steady. When that detection broke down, the warmup engine was effectively flying blind: it couldn't confirm healthy placement, couldn't safely advance your score, and couldn't trigger spam rescue on emails that needed it. For senders mid-ramp, this meant days of warmup that looked active on the surface but wasn't actually building the reputation your campaigns depend on.
What changed
- Placement detection now reads inbox and spam folders reliably across providers, so the warmup engine always knows where its test emails are landing. The score reflects what is actually happening in mailboxes, not gaps in the data.
- Spam rescue moves warmup emails that land in spam back to the inbox and records how many were recovered — a direct signal to receiving providers that your mail belongs in the inbox. This is one of the primary mechanisms that protects and builds sender reputation during ramp, and it now runs as intended.
- Health safeguards pause a mailbox that shows genuine deliverability problems rather than letting it continue in a degraded state — and resume it automatically after a cooldown period. A temporary hiccup no longer permanently derails a sender's ramp.
Why it matters for your campaigns
Warmup is the foundation for inbox placement at scale. The math is straightforward: a sender with a properly ramped reputation reaches the inbox; one that stalled during warmup starts getting filtered before your prospects ever see the subject line. That filtering compounds — a poor reputation today means worse placement tomorrow, which means fewer replies, which means fewer meetings booked.
Reliable placement detection means the warmup score reflects reality, the daily send limit ramps on schedule, and your campaigns launch from a sender that major mailbox providers already recognize as trustworthy. The difference between a fully warmed sender and one that stalled mid-ramp can be the difference between an 80% inbox rate and landing in spam for a significant share of your list.
What you should do
Nothing requires action. If a sending account previously showed a warmup score that seemed stuck despite clean sending, the detection fix means the system can now correctly read its placement and advance accordingly. Check the Warm Up tab on any connector to see the updated score and current daily target — the chart now shows a breakdown of sent, replied, and spam-rescued mail for the last seven days, giving you the full picture behind any score movement.