Email sending limits by provider
Every provider caps how much you can send. But the account cap is not a safe cold-email volume: the inbox-safe number is far lower, and you scale with more inboxes, not more per inbox. Pick a provider for the real numbers.
- Gmail (free @gmail.com)500 messages / 500 unique recipients per rolling 24-hour window. Counted on a sliding window, not at midnight; lockout clears 1-24h after you hit it.
- Google Workspace (Gmail, paid)2,000 messages sent per day and 2,000 external recipients per day per user. New/trial Workspace accounts are throttled to 500/day until the account establishes reputation.
- Outlook.com / Hotmail (free)~300 recipients per day (Microsoft does not publish an exact figure for free accounts). Brand-new accounts are throttled even lower until they build credibility.
- Microsoft 365 (Exchange Online, paid)10,000 recipients per day per user mailbox. Separately, a tenant-wide External Recipient Rate Limit (TERRL), rolled out from April 2025 and scaled by paid-license count, caps total external recipients per 24h across the tenant.
- Yahoo Mail (free)Yahoo deliberately does not publish exact figures; observed practical limits are ~100 emails/hour and ~500 emails/day per account. Via SMTP the documented cap is 500 outbound emails/day.
- Zoho Mail (paid / free)Outbound external mail is a DYNAMIC 50-500 emails/hour, adjusted by sender reputation, recipient engagement and contact quality (internal-org mail is 1,000/hour). There is no single fixed daily number; free plans sit at the low end of the dynamic range.
- Amazon SESSandbox (default for new accounts): 200 messages per 24h. Production starter quota (after approval): 50,000 messages per day, then auto-scaled upward by AWS as your reputation proves out.
- Twilio SendGridFree trial: 100 emails/day for 60 days, then you must upgrade (the permanent free plan was retired May 27, 2025). Essentials: ~50,000-100,000 emails/month. Pro: 100,000-2,500,000 emails/month. Caps are monthly volume, with per-email overage billing.
Find your safe daily volume.
Use the safe sending volume calculator to turn account caps into an inbox-safe number across your inboxes, then let Scheduler Zero pace the sending automatically.