Back to Tools

Email Warmup Calculator

Calculate an optimal email warmup schedule for new domains or IPs. Get a day-by-day sending plan to build sender reputation without triggering spam filters.

Email Warmup Calculator

Plan your email warmup schedule for new domains or IPs

Emails per day after warmup

30% daily increase - balanced approach

Like this tool? Try Sequenzy for free

AI-powered email marketing with Stripe integration, automations, and built-in analytics.

13

Days to target

50

Starting volume

51,717

Total during warmup

Warmup Schedule

DayDaily EmailsProgressCumulative
Day 150
50
Day 265
115
Day 385
200
Day 4110
310
Day 5143
453
Day 6186
639
Day 7241
880
Day 8314
1,194
Day 9408
1,602
Day 10530
2,132
Day 11689
2,821
Day 12896
3,717
Day 13Target reached1,000
4,717
Day 141,000
5,717
Day 151,000
6,717
Day 161,000
7,717
Day 171,000
8,717
Day 181,000
9,717
Day 191,000
10,717
Day 201,000
11,717
Day 211,000
12,717
Day 221,000
13,717
Day 231,000
14,717
Day 241,000
15,717
Day 251,000
16,717
Day 261,000
17,717
Day 271,000
18,717
Day 281,000
19,717
Day 291,000
20,717
Day 301,000
21,717

Showing first 30 days. Download CSV for full schedule.

Warmup Best Practices

  • • Send to engaged subscribers first (recent openers)
  • • Monitor bounce rates daily - pause if > 2%
  • • Check spam folder placement with seed lists
  • • Avoid cold outreach during warmup period
  • • Maintain consistent sending times each day

Why warmup?

  • New IPs/domains have no sending reputation
  • ISPs flag sudden high volume as spam behavior
  • Gradual increase builds trust with email providers
  • Rushing warmup can permanently damage deliverability

About this tool

Send 50,000 emails from a brand-new domain on day one and you'll land in spam everywhere. ISPs have never seen your domain before, have no reputation data, and will treat you like a spammer until you prove otherwise. Email warmup is the process of sending gradually increasing volumes over weeks, letting ISPs build a positive reputation profile for your domain and IPs. This calculator generates a day-by-day schedule based on your target volume, so you know exactly how many emails to send each day.

Why warmup is non-negotiable

Gmail, Microsoft, and Yahoo all track sender reputation at both the domain and IP level. When they see a new sender, they start with low trust and adjust based on engagement signals — opens, clicks, replies, and spam complaints. If your first emails get good engagement (because you're sending to your most active subscribers), the ISP raises your trust score and allows more volume. If they get ignored or marked as spam, your reputation tanks before it even starts. There's no shortcut around this process.

How a warmup schedule works

A typical warmup starts at 20-50 emails per day and roughly doubles every 2-3 days. By week 2, you're at a few hundred per day. By week 4, a few thousand. By week 6-8, you should be at your target volume. The exact ramp depends on your goal — warming up to 10,000/day takes about 4 weeks, while 100,000/day takes 6-8 weeks. During this time, send only to your most engaged subscribers — people who've opened or clicked in the last 30 days. Their positive engagement is what builds your reputation.

What to do before you start warming up

Authentication must be locked down before you send a single email. Set up SPF, DKIM, and DMARC for your sending domain. Verify your records with our DNS propagation checker. Set up a proper List-Unsubscribe header so recipients can opt out cleanly (required by Gmail and Yahoo). Check your domain age with a WHOIS lookup — ideally, your domain should be at least 30 days old before you start warming. And run your content through a spam word checker to avoid trigger words during this critical period.

Monitoring during warmup

Track these metrics daily: delivery rate (should stay above 95%), bounce rate (should stay below 2%), spam complaint rate (must stay under 0.1%), and open rate (should be consistently high since you're sending to engaged users). If any of these deteriorate, slow down — reduce volume by 50% and hold for a few days before resuming the ramp. Run weekly blacklist checks on your sending IPs. Use campaign analytics to track trends over the warmup period.

Frequently Asked Questions