Why Warmup Matters
A brand-new email inbox has no sending reputation. If you immediately start sending dozens of cold emails, mailbox providers (Google, Microsoft, Yahoo) will likely flag your messages as spam. Warmup gradually builds a positive sending reputation so your emails land in the primary inbox.
The Three Phases
Revrep uses a three-phase warmup system. Each inbox progresses through these phases automatically based on its age.
Phase 1: Cold
| Setting | Default |
|---|---|
| Duration | 14 days |
| Cold emails per day | 0 |
| Badge color | Blue |
During the Cold phase, the inbox is building initial reputation. No cold emails are sent. The inbox is being warmed through a warmup network — sending, receiving, and engaging with emails to establish trust with mailbox providers.
You cannot enroll contacts using a Cold inbox. The enrollment wizard will not show Cold inboxes as eligible senders.
Phase 2: Warm
| Setting | Default |
|---|---|
| Duration | Days 15 through 29 |
| Cold emails per day | Starts at ~3/day, ramps linearly toward 25/day |
| Badge color | Yellow/Orange |
The Warm phase gradually increases your daily sending limit. Each day, the inbox is allowed to send a few more emails than the day before. The exact daily limit is calculated based on the configured warm phase schedule — by default it ramps linearly from about 3 emails/day up to the Hot maximum.
Phase 3: Hot
| Setting | Default |
|---|---|
| Starts on | Day 30 |
| Cold emails per day | 25 |
| Daily variation | ±10% |
| Badge color | Green |
In the Hot phase, the inbox is fully warmed and operates at maximum capacity. The daily limit has a small random variation (±10% by default) built in to make your sending pattern look more natural — for example, a 25/day limit might be 23 one day and 27 the next.
This variation is deterministic per inbox per day, so the limit stays consistent throughout a single day even if checked multiple times.
Warmup Status Banner
If you are on a managed plan, a warmup status banner appears on your dashboard showing the current state of your inboxes:
- "Creating inboxes & starting warmup..." — No inboxes have been provisioned yet
- "Warming up.. outbound will begin on [date]" — At least one inbox is still in the Cold phase. The date shown is when the Cold phase ends.
- "Ramping up to full volume until [date]" — All inboxes are past Cold but still in the Warm phase
- No banner — All inboxes are Hot and at full capacity
Configuring Warmup
You can adjust warmup settings from your Settings page. The following options are available:
| Setting | What It Controls | Default |
|---|---|---|
| Cold Phase Length | Number of days in the Cold phase (0 sends/day) | 14 days |
| Hot Start Day | Day when the Hot phase begins (full volume) | Day 30 |
| Hot Max Emails/Day | Maximum emails per inbox per day in the Hot phase | 25 |
| Deviation % | Random daily variation around the max (for natural patterns) | 10% |
| Warm Phase Schedule | Per-day limits during the Warm phase (overrides the default linear ramp) | Linear ramp from ~3 to hot max |
Disabling Warmup
You can disable warmup entirely, which makes all inboxes use Hot-phase daily limits immediately. Only do this if your inboxes are already warmed up from another platform or service. Adding a brand-new inbox with warmup disabled will likely result in poor deliverability and spam placement.
Warmup Tracking
Revrep tracks the following metrics per inbox during warmup:
- Warmup state: Current phase (Cold, Warm, Hot)
- Emails sent today: Daily counter that resets each day
- Total emails sent: Lifetime counter since warmup started
- Active sending days: Number of days the inbox has actively sent
- Day count: Days since warmup was activated
These metrics are visible in the Analytics page and the enrollment inbox selector.
Key takeaway: Be patient with warmup. The 14-day Cold phase and gradual Warm ramp exist to protect your sending reputation. Rushing warmup leads to poor inbox placement that takes weeks to recover from.