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Email Warmup Calculator

Build a day-by-day ramp from a starting volume to your target, and check the target against the sending limits Google and Microsoft actually publish.

The ramp curve is a planning heuristic, not vendor guidance. No mailbox provider publishes a warmup schedule, so the shape below is arithmetic between the two volumes you give it, nothing more. What providers do publish are hard ceilings and reputation thresholds, and this tool checks your target against those. Treat the schedule as a plan to adjust against real bounce and complaint data, not a standard to hit.

Your ramp

Messages per day per mailbox once the ramp is finished.

messages/day

What you send on day one. A new mailbox usually starts in the tens, not the hundreds. This is your choice, not a published figure.

messages/day

How long you want the ramp to take. Longer is gentler; the arithmetic doesn't care, your recipients' spam buttons do.

weeks

5 for weekdays only, 7 for every day.

days
Curve shape

Steady percentage growth compounds, so early days stay small and later days climb fast. Equal steps adds the same number of messages every day.

Your schedule

Planning heuristic

A 6-week ramp over 30 sending days, from 20 to 1,000 messages a day, totalling 7,785 messages.

6 weeks · 30 sending days · 7,785 messages in total · about 14.4% more each sending day.

Week-by-week warmup ramp. Volumes are calculated from the values entered above, not published by any provider.
WeekPer day (start → end)Sending daysWeek total
120 → 345133
239 → 675261
377 → 1325514
4151 → 26051,009
5297 → 50951,980
6583 → 1,00053,888

Analyze these results with AI

Send this schedule to your AI assistant for a read on what to watch as you ramp.

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The limits this plan is checked against

These are published by the providers themselves. They are ceilings on volume, not warmup advice. No provider tells you how fast to approach them.

  • Google Workspace: 2,000 a day per mailbox. Daily sending limit per user account (500 on trial accounts).
  • Microsoft 365: 10,000 a day per mailbox. Recipient rate limit: 10,000 recipients per mailbox in a 24-hour window, which caps one-recipient messages at the same number.
  • Microsoft 365 also throttles submission at 30 messages a minute per mailbox, so a large daily figure has to be spread across the day rather than sent in one burst.

What decides whether the ramp works

  • Complaint rate. Google requires bulk senders to stay under 0.3% and recommends under 0.10%; Yahoo publishes the same 0.3% ceiling. That is a published number, unlike any ramp percentage. Track it as you climb with the deliverability calculator.
  • Bounces. Google’s own guidance when messages start bouncing or being deferred is to reduce volume until the error rate drops, which means the ramp is a plan to pause, not a schedule to force.
  • Authentication. Senders above 5,000 messages a day to Gmail need SPF, DKIM and DMARC in place. Warming a domain that fails authentication just builds a reputation faster. Check yours first.

Sources

Every limit and threshold quoted above comes from one of these pages. The ramp curve itself has no source, because none exists. It is arithmetic on your own inputs.

A warmup only builds reputation if the mail authenticates

Gmail and Yahoo require SPF, DKIM and DMARC from bulk senders. Palisade's agent finds every service sending as your domain, drafts the fixes, and proposes each policy step. You approve before anything ships.

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What is an email warmup calculator?

It plans the climb from a small starting volume to the volume you actually need, spread over as many weeks and sending days as you choose. New domains and new mailboxes have no sending history, so providers treat a sudden burst of mail as the signal it usually is. Ramping gives them time to build a picture instead. The curve this tool draws is arithmetic between your two numbers, because no mailbox provider publishes a warmup schedule to follow. The figures that are published are the daily sending limits, and your target gets checked against those. For the ramp in context, read how to warm up a new sending domain safely and the email warmup schedule guide, which sets out what providers do and do not publish. Before you start, make sure the mail authenticates: check SPF, DKIM and DMARC in one pass, and track your rates as volume rises with the deliverability calculator.

How many weeks should I set the ramp to?

Long enough that bounce and complaint rates stay flat while volume rises, which is a condition rather than a number. No mailbox provider publishes a warmup schedule, so any specific week count is someone's heuristic rather than vendor guidance; what providers publish are ceilings and reputation thresholds. The six-week default this calculator opens with is a starting shape, not a recommendation. Set the length that leaves you room to hold volume where it is the moment the numbers move, and treat the ramp as a plan to pause rather than a schedule to force. On whether warming helps at all, see does email warmup work.

How many emails can I send per day from Google Workspace?

Google documents a daily sending limit of 2,000 messages per user account, dropping to 500 on trial accounts. Separate limits apply to recipients: 10,000 total recipients per day, 3,000 external recipients per day, and 2,000 recipients on a single message with a maximum of 500 external. These are hard limits enforced by the platform, not reputation thresholds, and no amount of warming increases them.

How many emails can I send per day from Microsoft 365?

Exchange Online enforces a recipient rate limit of 10,000 recipients per mailbox in a rolling 24-hour window, which caps single-recipient messages at the same figure. Recipients on one message are customizable up to 1,000. There is also a message rate limit of 30 messages per minute per mailbox, so a large daily total has to be spread through the day rather than sent in one burst. Microsoft additionally applies a tenant-level external recipient limit that scales with your licence count.

Where does this calculator's curve come from?

Arithmetic on the two volumes you enter, and nothing else. Steady percentage growth compounds the same percentage each sending day between your start and your target; equal steps adds the same number of messages every day. Neither shape is vendor guidance, because no provider publishes one. Google's sender guidelines tell you to increase volume gradually and to reduce it when messages start bouncing or being deferred, without day-by-day numbers, and Microsoft publishes limits rather than a ramp. That gap is why warmup schedules vary so much between tools: they are all estimates. What you can hold anyone to are the published figures, which is why this calculator checks your target against those and labels the curve itself as arithmetic. For how the published guidance reads in full, see the email warmup schedule guide.

What should I watch while warming up?

Complaint rate first, because it has real published thresholds: Google requires bulk senders to stay under 0.3% and recommends under 0.10%, and Yahoo publishes the same 0.3% ceiling. Then hard bounces, which signal list quality and are the rate Amazon SES enforces against on your own sending account. Then engagement, since providers weigh whether people open and reply. If any of these move the wrong way, hold volume where it is rather than continuing up the ramp.

Do I need to warm up a new domain, a new IP, or both?

Both carry reputation, and which one dominates depends on how you send. On shared infrastructure like Google Workspace or Microsoft 365 you do not control the IP at all, so domain reputation is the thing you are building. On a dedicated IP through an ESP or your own server, the IP has its own history and needs its own ramp. A new domain on a new dedicated IP is the slowest case, because neither has a track record.

Does a warmup replace email authentication?

No, and warming an unauthenticated domain works against you. Google and Yahoo require SPF, DKIM and DMARC from senders of 5,000 or more messages a day. Volume without authentication builds a reputation on an identity mail providers cannot verify. Publish the records first, confirm they pass, then start the ramp.

Can warmup services or reply networks help?

Automated warmup networks send mail between accounts and mark it as important to simulate engagement. Mailbox providers describe artificial engagement as something they detect and act against, and Google's guidelines are explicit that senders should send only to people who asked for the mail. The safer ramp is real mail to real recipients who expect it, which is what this calculator plans for.