How Many Cold Emails Can You Send Per Day? Limits That Keep You Alive

You bought a domain, spun up a few inboxes, loaded three thousand leads, and hit send. By the afternoon your open rate had cratered and your replies were all bounces. The list was fine. The problem is that every mailbox provider was counting, and you blew past the number that keeps you in the inbox on the very first morning.

I build the sending setup behind cold email that has to land: the domains, the inboxes, the warmup, the part that decides whether a campaign reaches anyone at all. The daily sending limit that matters is not the one Google prints. It is the much smaller one your reputation can survive. Here are both, and the math for sending real volume without burning the domain your business runs on.

The short version: Google Workspace caps a paid account at 2,000 messages a day, and Microsoft 365 caps a mailbox at 10,000 recipients a day, but neither number keeps you out of spam. For cold outreach the real ceiling is a reputation limit, not a vendor limit: roughly 30 to 50 emails per inbox per day once the mailbox is warmed, reached over a two to four week ramp. You scale by adding inboxes and separate sending domains, not by pushing one inbox harder. Keep your spam complaint rate under 0.10 percent, never touch 0.30 percent, and authenticate every domain, because since February 2024 Gmail and Yahoo, and since May 2025 Outlook, reject bulk senders who do not.

What are the Google Workspace and Outlook sending limits?

Two numbers are fixed, enforced by the provider, and will bounce your mail the moment you cross them. On a paid Google Workspace account you can send 2,000 messages per day, counted over a rolling 24 hours, not a calendar day. A trial account gets 500. Separately, Google caps you at 3,000 external recipients a day and 2,000 unique external recipients a day, and a single message can reach at most 500 external addresses. Google’s limits page was last updated on July 10, 2026, so these are current.

Microsoft 365 counts differently. Exchange Online lets a mailbox reach 10,000 recipients per day, sends to at most 500 recipients per message by default (an admin can raise that to 1,000), and throttles you at 30 messages per minute. Microsoft’s own limits page, updated in 2026, tells high-volume senders to use a dedicated service instead of Exchange Online. That is a hint worth reading. These mailboxes were built for a person writing to people, not a machine writing to strangers.

Provider	Hard daily cap	Per message	Rate
Google Workspace, paid	2,000 messages, 3,000 external recipients	500 external recipients	rolling 24h
Google Workspace, trial	500 messages	500 external recipients	rolling 24h
Microsoft 365, Exchange Online	10,000 recipients	500, up to 1,000	30 per minute

The limit that actually matters is your reputation

You will never reach 2,000 cold sends from one inbox, because your reputation dies long before the cap. Mailbox providers watch how strangers react to you. Bounce too many, get marked as spam too often, and your mail stops reaching anyone, no matter how far under the vendor limit you are.

For a warmed cold-outreach inbox, keep the daily number low, somewhere around 30 to 50. The tools that do this for a living do not agree, which tells you it is a judgment call and not a law. Instantly caps a warmed inbox at 30 a day. Woodpecker starts new mailboxes at just 10 to 20. lemlist ramps a mailbox toward 100 a day once it is fully warmed. The spread is wide, so take the cautious end. Thirty to fifty from a warmed inbox holds your reputation, and pushing toward the high end is a bet you do not need to make.

How do you warm up a cold email inbox?

A brand-new mailbox has no reputation, and a sudden burst of cold mail from a name nobody has seen reads as spam by default. So you ramp. Start small, around ten emails a day, and raise the volume slowly. Postmark suggests doubling the volume each day while it is still tiny, then slowing to 20 to 50 percent a day as it grows, and pulling back 25 to 30 percent the moment your numbers slip. Most inboxes reach full cold volume in two to four weeks, and the warmup never really stops. It runs quietly underneath your live campaigns to hold the reputation you built. Skip it and you spend a reputation you do not have yet.

How many cold emails can you send per domain?

Once you know the per-inbox ceiling, scaling is arithmetic. You do not push one mailbox harder. You add mailboxes, and you spread them across domains. In the setups I run, two to three inboxes per sending domain, each warmed to 30 to 50 a day, is the safe ratio, which is roughly 60 to 150 sends per domain per day. To send more, you add more domains.

And you never send cold from the domain your business runs on. This is where cold outreach parts ways with regular bulk mail. For your own marketing and receipts, the move is to send from a subdomain and keep your root clean. For cold outreach to strangers, you go further and use separate secondary domains entirely, because a subdomain still shares reputation with its root, and a burned cold campaign can drag your real domain down with it. Buy a few lookalike domains, point them at the same brand, warm their inboxes, and keep every bit of cold-send risk off the name your customers actually reply to.

I once watched a founder run cold outreach straight from the company’s primary domain, because it was the account he already had. It worked for a week. Then the complaints added up, the domain’s reputation fell, and his real replies to paying customers started landing in spam. The cold campaign was cheap. Rebuilding the reputation of the domain his business ran on was not.

The thresholds that end you

Two numbers decide whether you keep sending. Keep your spam complaint rate, the share of people who hit the spam button, under 0.10 percent, and never let it reach 0.30 percent. Cross that ceiling and your delivery drops fast and recovers slowly.

And authenticate everything, because the rules changed and they are enforced. Since February 1, 2024, Gmail and Yahoo require any sender above 5,000 messages a day to pass SPF, DKIM, and DMARC and to carry a one-click unsubscribe. Since May 5, 2025, Microsoft’s Outlook enforces the same on high-volume senders to its consumer inboxes, routing non-compliant mail to Junk first and rejecting it later. The 5,000-a-day threshold is the line where you stop being a person and start being a bulk sender in their eyes, and the price of that title is proof of who you are.

Cold email is not a volume game you win by sending more. It is a reputation game you win by sending carefully. Stay under the per-inbox ceiling, warm every mailbox, spread the load across domains, keep your complaints near zero, and keep the risk off the domain you cannot afford to lose. Send like that and the inbox keeps letting you in. And once a reply lands, speed decides the deal.

Frequently asked questions

How many cold emails can I send per inbox and domain each day?

For a warmed cold-outreach mailbox, 30 to 50 messages a day is a conservative operating range, far below the provider cap. With two or three mailboxes, that produces roughly 60 to 150 messages per sending domain each day. These are practice-based ranges rather than provider guarantees. Scale gradually, watch bounces and complaints, and avoid cold outreach from the primary domain.

What are the Google Workspace and Outlook sending limits?

A paid Google Workspace account can send 2,000 messages a day over a rolling 24 hours, with 3,000 external recipients a day and 500 external recipients per message. A trial account gets 500. Microsoft 365 lets a mailbox reach 10,000 recipients a day, 500 per message by default, at 30 messages a minute. These are hard, enforced caps, updated in 2026, and they bounce mail once crossed.

How long does it take to warm up a cold email inbox?

Two to four weeks for most mailboxes. Start at around ten sends a day, double the volume early while it is tiny, then slow to 20 to 50 percent a day, pulling back if bounces or complaints climb. Then keep a light warmup running under your live campaigns, because reputation fades if you stop tending it.

Should I send cold email from a subdomain or a separate domain?

Use a separate secondary domain, not a subdomain, and never your primary. A subdomain still shares reputation with its root, so a burned cold campaign can pull your real domain down. Buy a few lookalike domains for cold outreach, warm their inboxes, and keep the risk off the name your customers reply to.

What spam complaint rate is safe for cold email?

Keep it under 0.10 percent and never let it reach 0.30 percent, the thresholds Google publishes for bulk senders. Above that ceiling your delivery collapses and recovers slowly. Mail only well-researched leads, honor unsubscribes within two days, and authenticate every domain with SPF, DKIM, and DMARC, required by Gmail and Yahoo since February 2024 and Outlook since May 2025.