Email warm-up schedule calculator: a week-by-week ramp
An email warm-up schedule starts a new domain or inbox small and raises daily volume about 50% at a time, holding each step for several sending days and never doubling. From 5 to 40 emails a day per inbox, that takes about five weeks. No mailbox provider publishes a warm-up schedule, so every step is an assumption you can change.
50% keeps each step well short of the doubling Google warns about.
- Weeks to full volume
- 5
- Full volume, all inboxes
- 200/day
- Week 1 sends, all inboxes
- 125
- Sends during ramp-up
- 1,750
Each inbox goes from 5 to 40 a day in 5 weeks; from week 6 the 5 inboxes send 200 a day between them.
| Week | Per inbox, per day | Per inbox, week | All inboxes, week |
|---|---|---|---|
| 1 | 5 | 25 | 125 |
| 2 | 8 | 40 | 200 |
| 3 | 12 | 60 | 300 |
| 4 | 18 | 90 | 450 |
| 5 | 27 | 135 | 675 |
| 6 | 40 | 200 | 1,000 |
| 7 | 40 | 200 | 1,000 |
Step back to the previous week’s volume if you see Gmail 4.7.28 deferrals, hard bounces above about 2% or spam complaints rising. Need more daily capacity? The inbox calculator works out how many inboxes you need.
Next step
7 weeks of careful ramp-up. One bounced list can undo it in a day.
Warm-up builds reputation slowly, and hard bounces on a young domain cost the most. Week 1 alone is 125 sends: verify the list before the first real campaign so every one of them reaches a real mailbox.
- Drop your list as a CSV
- See its rows, duplicates and bad formats, free
- 100 free email checks when you sign in with Google, no card
Ready to verify now? Verify the list
Sample result
5 inboxes ramp from 5 to 40 sends a day each, reaching 200 a day in total by week 6.
- Weeks to full volume
- 5
- Full volume, all inboxes
- 200/day
- Week 1 sends, all inboxes
- 125
What this means for you
Raising volume slowly builds sender reputation, so your mail is less likely to land in spam.
- Week-by-week ramp for every inbox
- Step size, hold days and sending days
- Warns when a step doubles volume
- Plans up to 26 weeks
- Warm-up
- Ramp
- Inboxes
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
How to build an email warmup schedule
- Enter how many inboxes you're warming up and the daily volume you want each to reach.
- Set where each inbox starts, how much to raise volume at each step, and how many sending days to hold each step.
- Set how many days a week you send. The schedule counts sending days, so weekends off stretch it out.
- Read the weeks to full volume and the table: per inbox per day, per inbox per week and all inboxes per week.
Example
- You enter
- 5 inboxes starting at 5 sends a day, target 40 each, raising 50% per step, holding each step 5 sending days, sending 5 days a week.
- You get
- A week-by-week ramp of 5, 8, 12, 18, 27 and 40 a day per inbox: 125 sends across all inboxes in week 1 and 200 a day from week 6, with 1,750 sends during the ramp.
- Limits
- Plans up to 26 weeks; runs in your browser.
How long does it take to warm up an email domain?
With the defaults, raising volume 50% a step and holding each step for a week of sending days, an inbox goes from 5 to 40 emails a day in about five weeks. No mailbox provider publishes a fixed period; the time depends on your start, target, step size and how long you hold each step, which is why the calculator lets you set all four.
The arithmetic: the number of increases is roughly LN(target/start)/LN(1+step), rounded up, and weeks to full volume is increases × hold days ÷ sending days per week. In a spreadsheet with start in A2, target in B2, step as a percentage in C2, hold days in D2 and sending days per week in E2, that's =ROUNDUP(LN(B2/A2)/LN(1+C2),0)*D2/E2. The calculator rounds each step to whole emails, so it can be one step shorter: from 5 to 40 at 50%, the formula gives six steps and the calculator five, because 27 × 1.5 rounds past the target.
How do you warm up an email domain?
Start with a low volume to engaged recipients and raise it gradually, which is what Google's Email sender guidelines say in their section "Increase sending volume slowly". They say to "start with a low sending volume to engaged users, and slowly increase the volume over time", that "immediately doubling previously sent volumes suddenly could result in rate limiting or reputation drops", and that "you can increase the sending volume more quickly when you send daily instead of weekly". Google publishes principles, not a timetable, and so do the other providers.
The defaults turn that into three rules of thumb: raise volume by 50% per step, which stays well short of doubling; hold each step for a week of sending days so problems show before you add more; and send the early volume to the recipients most likely to open and reply. From 5 a day the steps are 5, 8, 12, 18, 27 and 40, the same ramp as the cold-inbox table in our warm-up schedule guide.
How many emails a day should a warmed-up inbox send?
That target is your decision, not a published safe number. For cold email, platforms such as Instantly suggest 30 to 50 a day per account, and mailbox providers publish no cold-email limit at all. Google Workspace's hard cap is 2,000 messages per user per day and Microsoft 365's is 10,000 recipients, both far above sensible cold volume; the sending limits calculator lists them all. If the target times your inboxes doesn't reach the daily total you need, the cold email volume calculator works out how many inboxes and domains to add.
For a marketing domain or a dedicated IP heading to thousands a day, use one "inbox" and set the target to its daily volume. The same rules apply, and Google says the more you send, the more slowly you should increase. Google also tracks limits per domain and per IP, and an IP's quota is shared by every domain sending from it.
When should you slow down a warm-up?
Slow down as soon as receiving servers push back: Google's guidelines say that if messages start bouncing or being deferred, reduce volume until the error rate falls, then increase slowly again. In practice, drop back a step and hold for a few days if you see Gmail 421 4.7.28 rate-limit deferrals, other 421 or 451 deferrals rising, spam complaints above 0.1% in Google Postmaster Tools, or opens and replies falling while volume rises.
Hard bounces above about 2% mean the list needs cleaning, not more warm-up: a young domain has no history to absorb them. Our bounce rate calculator checks a campaign against the published platform limits.
Manual warm-up schedule or automated warm-up tool?
| Manual ramp of real mail (this schedule) | Automated warm-up tool | |
|---|---|---|
| What it sends | Real emails to real recipients | Emails between a pool of warm-up inboxes |
| What providers have said | Google's guidelines describe it | No major provider has said how it treats this traffic |
| Builds engagement with your audience | Yes | No, only within the pool |
| Effort | You pace the sends | Runs in the background |
Many senders use both: an automated tool for background history, and a gradual ramp of real mail to engaged, verified recipients.
Who uses this tool, and for what?
- Cold emailers
- Plan the ramp for a batch of new inboxes and know the week they can carry full volume, before booking campaigns against them.
- Agencies
- Give a client a dated, week-by-week plan for new sending domains, with total volume per week across every inbox, instead of "a few weeks".
- Marketers
- Ramp a new marketing domain or dedicated IP by setting one "inbox" to the domain's daily target, and pace the first sends to your most engaged subscribers.
- IT admins
- Moving mail to a new domain or provider? Use the schedule to raise outbound volume gradually instead of switching everything over on day one.
What can’t this tool tell you?
- The 50% step and one-week hold are rules of thumb built on Google's guidance, not a published schedule. No provider promises that following them avoids filtering.
- It plans volume only. It can't see deferrals, complaints or bounces, which are the signals that should slow you down.
- The schedule is capped at 26 weeks. A very low start with a high target and small steps can run past that.
- It assumes every inbox ramps in parallel from the same start. Staggered starts need separate runs.
Common questions
- How long does it take to warm up a new email domain?
- No mailbox provider publishes a fixed period. With the defaults here, raising 50% a step and holding each step a week, an inbox goes from 5 to 40 a day in five weeks. A marketing domain heading to tens of thousands a day takes longer, and any deferrals or complaints along the way add time.
- How do I warm up an email account?
- Start at a few emails a day to people likely to reply, raise the volume in steps of around 50%, and hold each step for several sending days while you watch bounces, deferrals and complaints. Authenticate the domain with SPF, DKIM and DMARC before you start.
- How fast can I increase sending volume?
- Google warns that suddenly doubling volume could cause rate limiting or reputation drops. A rise of around 50% at a time, held for several sending days, stays well short of that. Google also says daily senders can ramp faster than weekly ones.
- What is an email warmup schedule?
- A plan for how many emails each new inbox or domain sends per day, week by week, until it reaches its target volume. This calculator builds one from your start, target, step size and hold time, and shows the total across all inboxes.
- Do I need to warm up each inbox separately?
- Yes, each inbox builds its own history, and the domain builds one too. Google notes that DKIM and SPF quotas are specific to your domain. That's why the calculator ramps every inbox in parallel and shows the total.
- Do I need an IP warmup schedule?
- Only if you send from a dedicated IP. Google tracks volume per IP as well as per domain, so a new dedicated IP needs the same gradual ramp; on shared IPs from a sending platform, you warm up the domain and inboxes instead.
- Do automated warm-up tools replace a schedule?
- They add sending history between warm-up inboxes, and many cold email platforms build them in. No major provider has said how it treats that traffic, so use them alongside a gradual ramp of real mail to engaged recipients, not instead of it.
- What should I send during warm-up?
- Real messages to people likely to open and reply: colleagues and existing contacts first, then your best-fit, verified prospects. Bounces and complaints during warm-up do the most damage, so don't warm up on an unverified list.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
- Bulk verification with real SMTP mailbox checks
- Hard bounces removed before a send, not discovered after
- Catch-all, disposable and role detection on every row
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.