How many cold emails per day can you send safely?

What the providers actually allow

Google Workspace (Gmail)

• 2,000 messages per user per day; 500 on a trial account.
• 2,000 unique external recipients per day; 500 on a trial account.
• Limits run on a rolling 24 hours, and Google says they can change without notice.
• Hit one and the user can't send for up to 24 hours.
• Trial limits don't rise during the trial. They rise only after the domain has paid at least $100, and that can take up to 75 days.

Microsoft 365 (Exchange Online)

• 10,000 recipients per day per mailbox, and 30 messages per minute.
• A tenant-wide limit on external recipients per day that depends on how many licences you have; trial tenants are capped at 5,000.
• Mail sent from a default onmicrosoft.com domain is limited to 100 external recipients a day per organisation.
• Microsoft recommends a separate service for bulk or high-volume email to external recipients.

From Google Workspace Admin Help and Microsoft Learn. Checked 7 October 2026.

Why those limits are not a target

The limits decide when the provider stops you. Spam filtering decides, long before that, whether anyone sees what you sent. Filters judge a sender on how recipients behave: whether they open, reply, ignore, delete or mark as spam, and whether the addresses even exist. A new domain has no history, so a sudden volume of mail to strangers is exactly what spam looks like.

So the useful question isn't "how many can I send?" but "how many can I send while recipients keep treating it as wanted mail?"

How to set your own number

1. Separate it from your main domain. Send cold email from secondary domains, never the domain your customers and invoices depend on.
2. Start small on every new inbox. Send a little each day to begin with, to people likely to reply, and give a new domain weeks of gradual warm-up before real volume.
3. Spread volume across inboxes. Several inboxes each sending a modest amount look more like people than one inbox sending a lot.
4. Raise it only when the signals are good. Replies coming in, bounces near zero, nothing landing in spam in your own test inboxes. If any of those turn, hold or cut back.
5. Write the cap down. Decide the ceiling per inbox and the ramp in advance, so nobody pushes volume on a bad week. We set sending volume and warm-up practice in writing for every engagement.

The signals to watch

• Spam complaints. Gmail asks senders to keep the spam rate reported in Postmaster Tools below 0.10%, and never to reach 0.30% (Google).
• Bounces. Verify addresses before sending; a list that bounces tells providers you don't know who you're writing to.
• Where your own test messages land. Check inbox versus spam on Gmail and Outlook every week.
• Replies per person contacted. If it falls as volume rises, you've gone past what your list and message can carry.

Checked 7 October 2026.

Fewer, better emails usually win anyway

Volume is rarely what's missing. A short, researched list written to specifically will usually get more conversations than a large one written to generally, and it puts far less strain on your domain. What the reply-rate data shows about campaign size · The full deliverability check

Sources

• Google Workspace Admin Help, "Gmail sending limits in Google Workspace"
• Microsoft Learn, "Exchange Online limits"
• Google, "Email sender guidelines"

Checked 7 October 2026; re-checked every 90 days. Providers change these limits; check the current figure before relying on it.