/Free email deliverability tool
IP Warmup Calculator
Build a staged sending schedule for a new setup or a move to a new ESP, adjusted for your infrastructure, your audience, and your current sending health.
What your plan includes
- How much to send at each stage
- Which audience to start with
- When to hold, pause, or step back
Example plan
| Week | Daily volume | Send to | Watch |
|---|---|---|---|
| 1 | ~2,000 | Most engaged (30-day) | Complaints under 0.1%, bounces under 2% |
| 3 | ~12,000 | 90-day engaged | Spam-folder placement |
| 6 | ~100,000 | Full list (target reached) | Steady state |
Free warmup plan
Instant schedule
/Work with me
Need help with CRM deliverability?
Warm-up planSafe ramp aligned to your ESP and lists
CRM setupCustomer.io or Klaviyo implementation
MonitoringReputation, bounces, and lifecycle QA
Book a strategy call →
Operator-led rollout, not just a spreadsheet export.
CRM Implementation Playbook 2026
/Direct answer
How do you warm up a sending IP safely?
Start with your most engaged recipients, increase by at most 1.5× every 2–3 days, and pause if bounces approach 2% or complaints reach 0.1%. Shared IPs still need domain and audience discipline. Provider-managed dedicated IPs should follow the ESP's automatic ramp with your own sequencing and monitoring.
/Example
Example: warming a new dedicated IP to 100,000 emails a day over eight weeks
These volumes follow a 1.5× per stage ramp (2–3 day holds), aligned with Customer.io domain-warming guidance and the CRM implementation playbook. Most senders target less than this. Your pace depends on list size, engagement, and how metrics respond at each step.
| Week | Daily volume | Send to | Watch |
|---|---|---|---|
| 1 | ~100–225 | Most engaged (14–30 day) | Complaints under 0.1%, bounces under 2% |
| 2 | ~500 | 30 to 90-day engaged | Postmaster compliance status |
| 3 | ~1,100 | Active list majority | Deferrals or throttling |
| 4 | ~3,800 | Full active list | Spam-folder placement |
| 5 | ~8,600 | Full active list | Complaint rate holding |
| 6 | ~19,000 | Light inactive share (≤5%) | Bounce and deferral trends |
| 7 | ~65,000 | Near full list mix | Provider delivery by mailbox |
| 8 | ~100,000 | Full list (target reached) | Steady state; future jumps need their own ramp |
/Guide
Dedicated vs shared, and moving to a new ESP
Dedicated IP
You or your ESP control the ramp. Use a day-by-day ceiling only when you manage the IP yourself. If your provider warms it automatically, treat the schedule as audience sequencing and monitoring alongside that mechanism.
Shared IP
There's no individual address to warm up. The pool already carries an established reputation. What moves the needle is domain reputation and who you send to first, not an individual IP warmup curve.
Moving to a new ESP
Use the same cold 1.5× staged curve as a new setup. Quarantine inherited lists first. If bounce is at or above 2% or spam is at or above 0.1%, remediate before ramping — a faster migration schedule will not help.
/Resources
Deliverability resources
Benchmarks
- Spam complaints: < 0.1% (warning > 0.2%)
- Unsubscribes: < 1% (warning > 2%)
- Bounce rate: < 2% (danger > 5%)
- Open rate: > 25% (poor < 15%)
When You Need a Warm-Up
- CRM implementation or migration (for example to Customer.io)
- New sending subdomain (e.g.,
news.example.com) - Large list import or reactivation campaign
- Rebrand/domain change or >60 days inactivity
Seasonality Reference
- B2B SaaS: Low weekends, Q1 push
- E-commerce: Q4 surge; weekend promos
- Delivery/Logistics: Mid-week peaks
- FinTech: Month-end salary cycles
/FAQ
Frequently Asked Questions
/01What is IP warm-up and why do I need it?+
IP warm-up is the process of gradually increasing email volume from a new IP address or domain to establish sender reputation with ISPs. It's essential for new CRM implementations, domain changes, or after periods of inactivity to avoid spam filters and ensure high deliverability rates.
/02How long should an IP warm-up take?+
A safe IP warm-up usually takes about 50 to 60 days to reach roughly 100,000 emails a day when you start small and increase by no more than 1.5× every 2–3 days. Lower targets finish sooner. Duration also depends on list hygiene, complaint rate, and whether the domain is newly registered. The planner calculates the schedule from your target and risk inputs.
/03What are the key metrics to monitor during warm-up?+
Gauge the ramp on complaint rate, bounce rate, deferrals, and delivery by mailbox provider. Keep spam complaints below 0.1% (investigate approaching that line), and treat bounce rates approaching 2% as a hygiene problem. Open rate after Mail Privacy Protection is directional only, not a reason to accelerate volume. Track Google Postmaster Tools and authentication (SPF, DKIM, DMARC).
/04Can I skip IP warm-up if my volume is low?+
Even for low volumes, IP warm-up is recommended when using new IPs or domains. It establishes proper sender reputation from the start and prevents future deliverability issues as you scale. The warm-up process ensures you're following best practices from day one.
/05What happens if I send too much too quickly?+
Sending too much volume too quickly can trigger spam filters, damage your sender reputation, and result in emails being blocked or filtered to spam folders. This can take months to recover from and significantly impact your email marketing performance.
/06How do industry seasonality patterns affect warm-up?+
Different industries have different engagement patterns by weekday. The planner notes peak and low days for awareness, but it does not multiply daily volume by seasonality — that would create jumps above 1.5× (for example a quiet Sunday into a Monday), which inbox providers punish.
/07What's the warmup schedule for 100,000 emails?+
For 100,000 emails a day, plan about eight weeks. Start around 100 a day to your most engaged contacts, hold each stage for 2–3 days, then increase by at most 1.5×. Never double in a single day. Hold or step back if bounces approach 2% or complaints reach 0.1%. The example table above lays this out week by week. Customer.io supports a daily ramp of up to 60 days on broadcasts for this reason.
/08What if my ESP manages dedicated IP warmup?+
Your provider warms this IP for you, so you don't set the daily ceiling by hand. Amazon SES ramps a standard dedicated IP automatically over about 45 days. SendGrid's automated warmup throttles volume for you, but it needs another warmed IP on the account to lean on. Use a complementary plan for which audience to send at each stage and what to watch, so engagement stays strong while the provider handles the ramp.
/09Should I warm up with inactive contacts?+
No. Most inactive audiences teach mailbox providers to associate your IP with unengaged mail. Start with the active subset only. Bring inactive contacts in near the end, and keep them to a small share of each day. Treat it as list preparation before warmup.
/10When should I pause or step back?+
Pause if bounces exceed 2% or complaints reach 0.1%. Authenticate SPF, DKIM, and DMARC before you scale. If hard-bounce or spam rates are already elevated on a migration, fix the list and authentication first. A faster ramp will make things worse.
/Sources
Sources
- Customer.io domain warming — 1.5× stages, 2–3 day holds, up to 60-day broadcast ramp
- CRM Implementation Playbook — Deliverability — post-MPP thresholds and progressive warm schedule
- Google Postmaster Tools — domain reputation and user-reported spam rate
- SendGrid — dedicated IP warmup guidance (provider-managed IPs)
- Amazon SES — standard dedicated IP automatic ramp
- MXToolbox — DNS, SPF, DKIM, and blacklist checks
- DMARC monitoring — e.g. Postmark
- Seedlist testing — inbox vs spam placement