Track and manage IP address warmup schedules to build sender reputation gradually

IP warmup is the process of gradually increasing sending volume from a new IP address so that receiving mail servers build trust in your sender reputation. Starting at low volumes and ramping up over 30–60 days significantly reduces the risk of landing in spam folders.

Requires active session (dashboard only).

Why warmup matters

New IP addresses have no sending history. If you immediately send 100,000 emails from a fresh IP, inbox providers will likely block or bulk-folder your messages. A structured warmup schedule builds a positive reputation signal over time.

Typical warmup ramp:

Day	Max daily volume
1–2	50
3–5	200
6–7	500
8–14	2,000
15–21	5,000
22–30	10,000
30+	No limit (fully warmed)

Get warmup report

GET/api/warmup

Returns the current warmup state for all tracked IPs plus a pool-level capacity summary. progress_pct is the percentage of today's sending window already used.

Response fields

successboolean

true when the request succeeded.

ipsArray<object>

Tracked IPs. Each entry includes ip_address, domain, pool_name, status, daily_limit_today, sent_today, and progress_pct.

poolsobject

Per-pool capacity. Each pool reports pool, remaining, and capacity.

summaryobject

Aggregate counts: totalIPs, warming, active, paused, totalCapacityToday.

GET /api/warmup

{
  "success": true,
  "ips": [
    {
      "ip_address": "198.51.100.42",
      "domain": "mail.example.com",
      "pool_name": "transactional",
      "status": "warming",
      "daily_limit_today": 2000,
      "sent_today": 847,
      "progress_pct": 42
    }
  ],
  "pools": {
    "transactional": { "pool": "transactional", "remaining": 1153, "capacity": 2000 },
    "marketing":     { "pool": "marketing",     "remaining": 4200, "capacity": 5000 },
    "cold":          { "pool": "cold",           "remaining": 0,    "capacity": 0   }
  },
  "summary": {
    "totalIPs": 1,
    "warming": 1,
    "active": 0,
    "paused": 0,
    "totalCapacityToday": 7000
  }
}

Initialize an IP for warmup

POST/api/warmup

Request body

ipAddressstringbodyrequired

Valid IPv4 or IPv6 address.

domainstringbodyrequired

Sending domain associated with this IP.

poolNametransactional | marketing | coldbodyrequired

Which pool this IP belongs to.

targetDailyLimitintegerbodydefault: 50000

Target volume once fully warmed.

Response fields

successboolean

true when the IP was registered for warmup.

configobject

The warmup configuration: ip_address, domain, pool_name, status, daily_limit_today, started_at, target_daily_limit.

POST /api/warmup
Content-Type: application/json

{
  "success": true,
  "config": {
    "ip_address": "198.51.100.42",
    "domain": "mail.example.com",
    "pool_name": "transactional",
    "status": "warming",
    "daily_limit_today": 50,
    "started_at": "2025-06-14T00:00:00Z",
    "target_daily_limit": 50000
  }
}

Pause or resume an IP

PUT/api/warmup

Pause halts the warmup schedule; resume continues from the current day.

Request body

ipAddressstringbodyrequired

The IP to act on.

actionpause | resumebodyrequired

Pause halts the warmup schedule; resume continues from the current day.

Response fields

successboolean

true when the action was applied.

messagestring

Human-readable confirmation of the action.

{ "ipAddress": "198.51.100.42", "action": "pause" }

{ "success": true, "message": "IP warmup paused" }

Pausing an IP does not reset its warmup progress. Resuming picks up where the schedule left off. If an IP is paused for more than 7 days, consider restarting the warmup from day 1 to avoid reputation decay.

Remove an IP from warmup tracking

DELETE/api/warmup

Removes the IP from warmup tracking. The IP remains in its sending pool but is no longer subject to daily ramp limits. Use this when an IP has completed warmup and is operating at full capacity.

Query parameters

ipstringqueryrequired

The IP address to remove from warmup tracking.

DELETE /api/warmup?ip=198.51.100.42

IP pool types

Pool	Use case
`transactional`	Welcome emails, password resets, order receipts — high-priority deliverability
`marketing`	Newsletters, promotional campaigns, drip sequences
`cold`	Outreach to contacts who have never interacted with your brand

Example: start a warmup

curl -X POST /api/warmup \
  -H "Content-Type: application/json" \
  -d '{
    "ipAddress": "198.51.100.42",
    "domain": "mail.example.com",
    "poolName": "transactional",
    "targetDailyLimit": 50000
  }'

const res = await fetch('/api/warmup', {
  method: 'POST',
  credentials: 'include',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    ipAddress: '198.51.100.42',
    domain: 'mail.example.com',
    poolName: 'transactional',
    targetDailyLimit: 50000,
  }),
});
const { config } = await res.json();
console.log(`Warmup started. Today's limit: ${config.daily_limit_today}`);

IP Warmup

Why warmup matters

Get warmup report

Initialize an IP for warmup

Pause or resume an IP

Remove an IP from warmup tracking

IP pool types

Example: start a warmup