How many cold emails per day should one inbox send?
Between 25 and 50 a day, according to four of the five cold email vendors we checked, with Instantly's 30 in the middle; the fifth, Mailreach, says about 100. That range is vendor advice. The providers' hard caps are far higher: Google Workspace lets a user send 2,000 messages a day, or 500 on a trial account (Google, page updated 13 October 2026), and Exchange Online lets a mailbox send to 10,000 recipients a day (Microsoft, updated 19 October 2026).
The gap between those two kinds of number is the whole question. A provider cap is where sending stops: Google says a Workspace user who hits a limit can't send new messages for up to 24 hours. The vendor numbers are each company's judgement of what keeps a mailbox out of the spam folder over months. Mailreach, a warm-up vendor, makes the point with Google's own figure: it says that sending 2,000 cold emails a day from Google Workspace would likely put you in recipients' spam folders within a week.
None of the vendors below cites an independent study. Two of them, Woodpecker and Smartlead, publish data from their own users, covered further down. The rest give a number without data.
What do cold email tools recommend per inbox?
Five vendors we checked publish a per-inbox number. Here is each one in its own terms, with the date shown on its page.
| Vendor | Daily cold emails per inbox | Conditions and notes | Page date |
|---|---|---|---|
| Instantly help centre | 30 campaign emails per account; up to 20 on its own AirMail mailboxes | Warm-up emails don't count. An optional Campaign Slow Ramp adds 2 emails a day until the limit is reached. | Checked 20 Oct 2026 |
| Woodpecker | 25 to 35; never more than 50 | For 300 a day, it suggests 10 mailboxes at 30 each. | Published 31 Aug 2026 |
| lemlist help centre | Start at 10 to 15, add 5 a week, cap at 25 to 30 | Warm-up plus campaigns at or below 50 per mailbox. A domain under a month old stays under 100 a day across all its mailboxes. | Checked 20 Oct 2026 |
| Smartlead | Up to 50; less while a new mailbox ramps up | Keep any one sending domain under about 500 a day. | Published 25 Sep 2026 |
| Mailreach | About 100, once the inbox is warmed up | Run warm-up alongside, and spread volume across addresses on different domains. | Updated 11 Feb 2026 |
Four of the five land between 25 and 50, and none except Mailreach advises more than 50 from one inbox. Mailreach is the outlier at about 100, and it ties that number to running warm-up in parallel. Each of these companies sells sending or warm-up software, so read the numbers as product advice from people with a stake in your volume.
The vendors also count different things. Instantly's 30 excludes warm-up emails; lemlist's ceiling of 50 includes them. Smartlead and Woodpecker give a per-mailbox ceiling, Smartlead adds a per-domain one, and lemlist caps a domain under a month old at 100 a day.
What does platform data say about daily volume?
Smartlead's data suggests most senders on its platform send less than the advice allows, and Woodpecker's links higher daily volume with lower reply rates. Neither dataset is independent.
- Smartlead. Its per-day guide says most mailboxes send far less than its ceiling of 50, and its warm-up benchmark page, built from more than 850 million emails sent through Smartlead, says the median mailbox sends about 14 cold emails a day and the heaviest 10% send 42. The page includes only senders with at least 500 emails in the period, and gives no dates for that period.
- Woodpecker. Its adaptive sending page charts median reply rate against average emails a day per mailbox, across 7,676 mailboxes that sent at least 500 emails in 90 days, under the heading that reply rates fall as daily volume per mailbox rises. Woodpecker notes that different use cases are mixed in, and that some low-volume mailboxes are automation or inbound. The page doesn't say which 90 days.
Neither dataset shows cause. A mailbox sending 15 a day may get more replies because its owner writes to a tighter list; the volume itself may not be the reason. Use both as a picture of what senders on those platforms do.
Why do vendors advise so far below the provider caps?
Because a cap only tells you when sending stops, while reputation is judged on signals the providers publish only in part. Here is what the providers do say.
- Spam rate. Google's email sender guidelines, which cover mail sent to personal Gmail accounts, require a spam rate reported in Postmaster Tools below 0.3% and recommend keeping it below 0.1%.
- Steady sending. The same guidelines ask large senders to send at a consistent rate and avoid sending in bursts.
- Per-domain tracking. Google says Gmail tracks volume, feedback and limits per domain and IP address, and that DKIM and SPF quotas are specific to your domain.
- Not a bulk tool. Microsoft's limits page says Exchange Online isn't suited to bulk-mailing scenarios.
There is a practical reason too: follow-ups use the same daily budget as first emails. Google's 2,000-a-day limit counts messages, and lemlist's own worked example counts first emails and follow-ups against one daily limit. At 30 sends a day with a three-email sequence, once every step is running, about a third of each day's sends go to new people. That is roughly 10 new people a day, or 50 in a five-day week.
Where does Siela's 150 a day sit?
Above every recommendation in the table, and far below Google's cap. Siela's AI SDR sends up to 150 emails a day per Gmail mailbox, 2 to 5 minutes apart, within the daily goal the owner sets. That is the most it will send from one mailbox. It is a ceiling, not a target, and for cold outreach from one inbox we would stay well below it.
Some arithmetic to place it: 150 is three times the ceiling of 50 that Woodpecker and Smartlead give, one and a half times Mailreach's 100, and 7.5% of Google Workspace's 2,000. At 2 to 5 minutes apart, 150 emails take roughly 5 to 12.5 hours to go out, so the sends spread across the day instead of leaving in one batch.
Our advice is to start a warmed-up mailbox on an established domain well below the maximum: a daily goal of 20 to 30, from just above lemlist's starting range up to Instantly's 30. On a brand-new domain, start lower and build up over several weeks. lemlist and Smartlead both start a new mailbox below their own ceilings, and Mailreach's example ramps a new campaign from 20 a day. A few weeks at that pace gives you bounce and reply data before you raise it. The daily goal is a target, not a quota, and the agent doesn't pad the list to reach it; it emails only work addresses it has verified as deliverable. Raise it by about 5 once a week, only while bounces and spam placement stay flat, and add a mailbox rather than going past about 30.
How to pick your daily number this week
Work back from how many new people you want to reach, then set a per-inbox number you can defend. These steps are our advice.
Start from new people per week
Decide how many new prospects you want to reach each week, then multiply by the emails in your sequence. Fifty new people a week with three emails each is 150 sends, or 30 a day over five days. Our guide to cold email sequences covers how many steps you need.
Pick a starting number per inbox
For a warmed-up mailbox on a domain that already sends email, start at about 20 a day. That sits between lemlist's 10 to 15 starting range and Instantly's recommended 30.
Count everything the mailbox sends
Google's daily limit includes mail sent from aliases, by delegates and by the vacation responder. lemlist counts warm-up and campaigns together against its 50-a-day ceiling. Add your manual replies and follow-ups to the total.
Spread sends across the day
Set a gap between sends so a day's volume goes out over hours. Google asks large senders to send at a consistent rate and avoid bursts. Check your sending tool for a gap setting; Instantly, for example, has a minimum wait time for accounts used in several campaigns, with a default of 1 minute.
Add inboxes before raising volume
If you need more, add mailboxes. Woodpecker's example is 300 a day from 10 mailboxes at 30 each, and Smartlead suggests keeping each domain under about 500 a day.
Check weekly before raising
Look at bounces, replies and, if you email personal Gmail addresses, your spam rate in Google Postmaster Tools. If all three are steady, raise your daily number by 5, the weekly step lemlist uses, up to about 30.
Frequently asked questions
How many cold emails per day should a new inbox send?
lemlist's help centre says none until warm-up is finished, then 10 to 15 a day, adding 5 a week up to a cap of 25 to 30. Woodpecker says a new mailbox should warm up before running campaigns and then follow its usual 25 to 35. Smartlead says a new mailbox should start below its ceiling of 50 and build up.
Do follow-up emails count toward the daily sending limit?
Yes. Google Workspace's daily limit counts the messages a user sends, including mail sent from aliases, by delegates and by the vacation responder, and its page lists no exception for follow-ups. lemlist's worked example counts first emails and follow-ups against the same daily limit, which is why a longer sequence reaches fewer new people each day.
Do warm-up emails count toward the daily limit?
In the vendors' own limits, no: Instantly says warm-up emails don't count toward its account and campaign limits, and lemlist says lemwarm emails don't count toward its global daily limit. lemlist still advises keeping warm-up plus campaigns at or below 50 a day per mailbox. Google's Workspace page names no exception for warm-up tools.
How many inboxes do I need to send 300 cold emails a day?
At 30 a day per mailbox, 10 inboxes, which is the example Woodpecker gives. At 50 a day, the ceiling Woodpecker and Smartlead set, six inboxes. Smartlead also advises keeping any single domain under about 500 cold emails a day, so 300 can sit on one domain if it is spread across several mailboxes.
Is 100 cold emails a day from one inbox too many?
It depends whose advice you follow. Mailreach treats about 100 a day as its recommended maximum for a warmed-up inbox that keeps running warm-up. Woodpecker says never to send more than 50 a day from one mailbox, and Smartlead also puts its ceiling at 50. Google Workspace's hard cap of 2,000 messages a day is far above either figure.
Sources
- Google Workspace Help: Gmail sending limits in Google Workspace (updated 13 Oct 2026)
- Gmail Help: Email sender guidelines (checked 20 Oct 2026)
- Microsoft Learn: Exchange Online limits (updated 19 Oct 2026)
- Instantly Help Center: Account and Campaign Limits (checked 20 Oct 2026)
- Woodpecker: How many cold emails per day? Adaptive sending (published 31 Aug 2026)
- lemlist Help Center: Understand sending limits in lemlist (checked 20 Oct 2026)
- lemlist Help Center: Set your global daily send limit (checked 20 Oct 2026)
- Smartlead: How Many Cold Emails Should You Send Per Day Per Domain? (published 25 Sep 2026)
- Smartlead Benchmarks: How long should you warm up an email domain before a campaign? (checked 20 Oct 2026)
- Mailreach: How many cold emails to send per day? (updated 11 Feb 2026)
- Siela: AI SDR (checked 20 Oct 2026)