How your warmup daily volume is decided

What is the difference between a target and a daily volume?

The target is the number you set in warmup settings: the volume you want this mailbox to reach eventually. The daily volume is the number warmup will actually send today.

They are different on purpose. If a mailbox with no sending history started at your target on day one, mailbox providers would read that as exactly what it looks like — a brand-new address suddenly sending mail — and filter it. So the target is a destination, and the daily volume walks towards it.

The target is also a ceiling, not just a goal: if you set a target of 10, warmup will never send more than 10, however long it runs. Lowering your target lowers today’s volume immediately; raising it does not raise today’s volume, because the curve still has to get there.

How fast does the volume climb?

The curve below is the default profile: a new sending domain, normal ramp speed, target 40. “Week” means a week of sending days, not a week on the calendar — the ramp only advances on days the mailbox actually sends, so a mailbox that could not sign in for four days is four days behind where the calendar says it is.

Your own curve can be steeper or gentler than this one, because two settings change it: the warmup mode the mailbox is in, and the ramp speed you chose.

Starting volume and ceiling by warmup mode

Ramp speed changes how big each step is, not where the mailbox ends up. On conservative the volume rises by at least one email every two sending days, on normal by at least two, on aggressive by at least three. Aggressive does not raise the ceiling — it only arrives sooner, and on a young domain arriving sooner is the risk you are trying to avoid.

Why is today’s number lower than my target?

Because something else is currently the lower ceiling. WarmySender works out every ceiling that applies, sends the lowest one, and tells you which one bound. Here is the whole vocabulary of reasons the product can show, in the order it prefers them — the top of the table is the most restrictive.

How does a mailbox earn its full target?

Standard warmup modes have a conservative ceiling because most mailboxes running them are new or recovering. A mailbox that has proved itself is allowed past that ceiling to your configured target. It qualifies when all of the following are true at once:

• the mailbox has been warming for at least 14 days;
• it has at least 7 days of actual sending behind it;
• fewer than 2% of its warmup emails are landing in spam;
• fewer than 1% of them are bouncing;
• it has moved into maintenance warmup.

Once all five hold, the ceiling becomes your target — up to an absolute maximum of 120 warmup emails a day. That last figure is a hard stop: no mailbox sends more warmup than that, whatever the target says, because past that point extra volume from a single address stops helping reputation and starts hurting it.

Why did my warmup volume go down?

Volume falls for one of four reasons, all of them deliberate:

• Placement slipped. More warmup mail started landing in spam, so the daily number dropped to protect the mailbox. It climbs back on its own once placement recovers.
• The mode changed. A mailbox moved into recovery, or out of a mode with a higher ceiling, and the new mode’s ceiling is lower.
• You lowered the target. The target is a hard ceiling and takes effect immediately.
• More mailboxes joined the same domain. The domain’s share is split between everything warming on it, so adding a fourth mailbox lowers the other three.

What does not lower it: reaching your target, a quiet day, or a weekend. Warmup runs every day of the week.

Why is my mailbox held at up to 3 warmup emails a day?

Because a few of its recent warmup emails landed in spam, and there is not yet enough mail to tell whether that is a real pattern. Rather than cut the mailbox to a trickle on a handful of results, WarmySender keeps it at up to 3 warmup emails a day — never more than its normal ramp for its age — so it keeps building a real picture. The mailbox page says so in one line, with the numbers behind it, for example: “Held at up to 3 a day while we confirm placement: 1 of the last 12 warmup emails landed in spam. Volume steps up again once the last 7 days are clean.”

• What lifts it: a clean week. The check looks at the last 7 days, so once those days hold no spam landings (or only one among plenty of inbox placements), volume steps back up on its own.
• Why it can last longer than a week: each new spam landing stays in that 7-day window for 7 days. A mailbox that has an occasional spam landing every few days stays held until it has a full clean week.
• What helps: leave warmup running, check the domain’s SPF, DKIM and DMARC records, and ease off cold sending from that mailbox. Switching warmup off or re-adding the mailbox restarts nothing and only slows the clean week down.

If enough mail lands in spam to be sure it is a pattern, the mailbox moves to the stricter hold described in the table above, where it sends 1 warmup email a day until placement recovers.

Which providers put my warmup emails in spam?

On your Warmup page, click the mailbox to open its warmup details: “Where your warmup emails landed” splits the last 14 days by the provider of the mailbox that received each email — Google, Microsoft, and other providers. Each shows how many warmup emails went there, how many reached the inbox, and how many landed in spam.

To see it for all your mailboxes at once, open the Analytics tab on your Warmup page: “Where your warmup emails landed, by the receiving provider” shows the same split for every warmup mailbox together. The provider filter at the top of that tab answers a different question — it picks which of your mailboxes to include, grouped by their own email provider: Google, Microsoft, or other providers. A Google Workspace mailbox connected with an app password counts as Google.

• Spam means landed in spam at least once. Warmup moves its own emails out of spam folders, so an email can land in spam and end up in the inbox later. It still counts as a spam landing here, because where it first landed is what matters for your reputation.
• “Not confirmed yet” means we have not confirmed a folder for that email yet. It is not counted as inbox or spam.
• One provider standing out is useful: if the spam landings cluster at one provider, that provider is the one filtering your mail, and its own sender guidance is the place to start.

You can ask your AI agent the same question in plain language — “which providers are putting my warmup in spam?” — and it reads the same numbers.

Why does one provider put almost all my warmup emails in spam?

When one provider sends most warmup emails from some mailboxes to spam while the same warmup stays out of spam at that provider for other senders, it usually reflects how that provider currently rates those sending domains or the mail server they send through. Warmup emails are written, timed and paced by the same system for every sender, so a gap this large points to how the provider sees the domains and the server, not to the emails themselves.

What we notice: when the gap is large and clear, the Warmup page says so at the top of the mailbox list and on the Analytics tab, and the notifications bell lets you know the first time it happens. It shows the numbers next to the WarmySender-wide figure for the same provider and the same days, for example: “At Google, 482 of 501 warmup emails from these mailboxes landed in spam (96.2%). Across WarmySender over the same days, 98.6% of warmup emails sent to Google stayed out of spam.”

What we already do: those mailboxes are slowed down automatically to protect them, with the badge “Cooling down — slowed on purpose while warmup lands in spam”, and their volume rises again on its own as fewer emails land in spam. A provider’s view can improve over time.

Things that commonly play a part: brand-new domains with no sending history yet, domains whose earlier sending the provider is still weighing, or a mail server shared with many other senders. Valid SPF, DKIM and DMARC records are necessary but do not by themselves earn trust. How many mailboxes you add at once is not, on its own, what decides this.

What you can try:

• Keep warmup on. While emails land in spam we keep volume low on purpose and raise it again as placement improves, so leaving it running is the quickest way back. Switching warmup off or removing and re-adding the mailboxes does not change how the provider rates them.
• Ask the company that hosts these mailboxes how that provider rates the mail server they send through, and whether it is shared with other senders.
• Check how the provider rates these domains. For Google, the free Google Postmaster Tools shows how Google rates a domain once it sends enough mail to personal Gmail addresses; at warmup volumes it may show no data yet, which is not a clean bill of health.
• Hold off on campaigns from those mailboxes until placement at that provider improves.

We only show this when both sides have a real sample and the provider is treating everyone else’s warmup well over the same days. If that provider is filtering warmup for many senders, we do not show it.

I added a lot of mailboxes at once. What should I expect in the first weeks?

Each new mailbox starts small — about one warmup email a day — and grows gradually over the next few weeks, the same as a mailbox added on its own. Adding many mailboxes at once does not speed that up or slow it down.

• The first week is when providers form a view. Gmail, Outlook and other providers decide how much they trust new domains and the mail server they send through. You can see where warmup lands at each provider from day one: click a mailbox on the Warmup page, or open the Analytics tab for all of them together.
• If warmup starts landing in spam, we slow those mailboxes down automatically and your notifications bell tells you, with the numbers. The badge on each one reads “Cooling down — slowed on purpose while warmup lands in spam”. That is protection, not a fault.
• Keep warmup running for at least 2–3 weeks before starting campaigns from new mailboxes.

For example: you connect 60 mailboxes on 20 new domains on Monday. On Monday each sends about one warmup email; by the end of the first week most send a handful a day. If one provider starts putting them in spam on Tuesday, your bell tells you that day, those mailboxes drop to a trickle, and their volume climbs again as placement improves.

Why do warmup emails trickle out through the day?

Because a day’s allowance sent in one burst looks like automation, and a day’s allowance spread out looks like a person. Warmup deliberately paces the day’s emails across your sending hours, which is why the count is low in the morning and only reaches the daily figure late on. The daily total is not reduced by this — it is the same number, arriving gradually.

Checking the count at 9am and concluding that warmup is broken is the single most common false alarm. Compare full days, not part-days.

Does pausing warmup reset my progress?

No. Progress is measured in sending days, not calendar days. A mailbox that has completed 12 sending days and then pauses for a fortnight comes back on sending day 12, not day 26 and not day 1. Nothing is lost, and nothing is gained by waiting either.

There is one moderating step: after a long gap, volume steps back up over about a week rather than resuming at the old number, because a silent mailbox that suddenly sends 40 emails is exactly the pattern filters look for.

Frequently asked questions

Why is my warmup daily limit lower than the target I set?

Because a lower ceiling is currently binding, and the mailbox tells you which one. The most common by far is simply that the mailbox is still ramping — the curve grows every two sending days on its own. The next most common are the warmup mode’s own ceiling, the domain’s volume being shared between several mailboxes warming at once, and the domain not yet signing its mail. Every one of them lifts without you doing anything, except the signing record, which you add once.

Can I set warmup to 100 emails a day?

You can set the target there, and a mailbox that has earned its uplift can reach it — the hard ceiling is 120 a day. But it will not start there. The mailbox still walks the curve from its mode’s starting volume, and it still has to satisfy the health conditions (14 days old, 7 sending days, spam under 2%, bounces under 1%, maintenance mode) before it is allowed past the standard ceiling. Setting a high target does not skip any of that.

How long does warmup take to reach full speed?

About six weeks of sending days for a new domain, arriving at 40 a day. A new mailbox on an established domain starts higher and settles at 60, taking about nine weeks. Maintenance warmup gets to its ceiling in about three weeks. In every case it is sending days that count, so a mailbox that spends a week disconnected is a week behind the calendar.

Why is warmup sending only a handful of emails this morning?

Because the day’s allowance is spread across your sending hours rather than sent in one go. This is intentional pacing and it does not reduce the daily total. Judge the number at the end of a full day, not partway through one.

Several mailboxes on one domain are all warming slowly. Why?

They are sharing one domain’s volume rather than each getting their own. A domain with four mailboxes warming at once gives each a quarter of what a single mailbox would get, because it is the domain’s reputation that the receiving side is judging, not each address separately. Warming them in smaller groups, or letting the earlier ones finish first, gets every mailbox to full speed sooner than starting all four together.

Does warmup volume come out of my campaign sending allowance?

Yes — warmup and cold campaign emails share one per-mailbox daily budget, so a mailbox running 40 warmup emails has 40 fewer available for campaigns that day. That is worth planning around when you size your mailboxes, and it is another reason the answer to “I need more volume” is almost always another mailbox rather than a higher number on this one.

My mailbox has been held at 3 warmup emails a day for weeks. Why?

Because the check behind it looks at the last 7 days, and a mailbox with an occasional spam landing every few days never gets a clean week. Each spam landing stays in that window for 7 days, so the hold continues until a full week passes with no spam landings, or with only one among plenty of inbox placements. The mailbox’s warmup details show how many of the last week’s checked emails landed in spam and which providers they landed at, so you can see what is keeping it there.

I added many mailboxes at once. Will that land them in spam?

Not on its own. Each new mailbox starts at about one warmup email a day and grows gradually, however many you add together. What decides placement in the first weeks is how Gmail, Outlook and other providers rate the new domains and the mail server they send through. If warmup starts landing in spam, WarmySender slows those mailboxes down automatically and your notifications bell tells you. Keep warmup running for at least 2–3 weeks before starting campaigns.

Related guides

• How many cold emails can I send per day? — the cold-sending side of the same budget
• Warmup is on but no emails are arriving
• Why your warmup can pause
• What is my mailbox warmup score?
• Why is my warmup bounce rate high?
• Full documentation