Email Sending Limits Reference Guide
Interactive, searchable reference for daily and hourly sending limits across Google Workspace, Microsoft 365, Outlook.com, Zoho, and Yahoo — by account type, method, and plan.
Showing 17 of 17 entries
| Provider | Plan | Daily Limit | Hourly Rate | Recipients/Msg | SMTP Relay |
|---|---|---|---|---|---|
| Google Workspace | Business Starter | 2,000 | ~83/hr (no official limit) | 500 external | 10,000/day (via SMTP relay service) |
| Google Workspace | Business Standard | 2,000 | ~83/hr | 500 external | 10,000/day (via SMTP relay service) |
| Google Workspace | Business Plus | 2,000 | ~83/hr | 500 external | 10,000/day (via SMTP relay service) |
| Google Workspace | Enterprise | 2,000 | ~83/hr | 500 external | 10,000/day (configurable) |
| Gmail (Free) | Free Personal | 500 | ~20/hr | 500 | Not available |
| Microsoft 365 | Business Basic | 10,000 | 30/min (1,800/hr) | 500 external | 10,000/day (via connectors) |
| Microsoft 365 | Business Standard | 10,000 | 30/min (1,800/hr) | 500 external | 10,000/day |
| Microsoft 365 | Business Premium | 10,000 | 30/min (1,800/hr) | 500 external | 10,000/day |
| Microsoft 365 | Enterprise E3/E5 | 10,000 | 30/min (1,800/hr) | 500 external | 10,000/day (configurable) |
| Outlook.com | Free | 300 | 30/hr | 100 | Not available |
| Zoho Mail | Free | 50 | 10/hr | 10 | Not available |
| Zoho Mail | Workplace | 500–1,000 | ~40/hr | 50 per message | Limited via ZeptoMail |
| Yahoo Mail | Free | 500 | 100/hr | 100 | Not available |
| Amazon SES | Sandbox | 200 | 1/second (3,600/hr) | Verified only | N/A (IS the relay) |
| Amazon SES | Production | 50,000+ (scalable) | 14/second default (50,400/hr) | 50 per API call | N/A (IS the relay) |
| SendGrid | Free | 100 | ~10/hr | 1,000 | Yes |
| SendGrid | Essentials | 100,000/mo (~3,333/day) | Not rate-limited (reputation-based) | 1,000 | Yes |
Important Notes
Google Workspace (Business Starter): Rolling 24h window. Limits reset gradually, not all at midnight. Warmup new accounts slowly.
Google Workspace (Business Standard): Same sending limits as Starter. Higher storage tiers. SMTP relay supports higher throughput.
Google Workspace (Business Plus): Same sending limits. Includes Vault for retention. SMTP relay recommended for volume.
Google Workspace (Enterprise): Custom SMTP relay limits can be negotiated. Contact Google sales for higher throughput.
Gmail (Free) (Free Personal): Not suitable for cold email. Account suspension risk is very high.
Microsoft 365 (Business Basic): Generous limits but strict rate limiting per minute. Burst sending will trigger throttling.
Microsoft 365 (Business Standard): Same limits as Basic. Desktop Office apps included. Use Send As for alias sending.
Microsoft 365 (Business Premium): Includes Intune + Azure AD P1. No higher sending limits vs. Standard.
Microsoft 365 (Enterprise E3/E5): Enterprise support can adjust limits for high-volume senders. Request via support ticket.
Outlook.com (Free): Extremely restrictive. Microsoft aggressively suspends for outbound bulk. Not suitable for cold email.
Zoho Mail (Free): Free tier is for personal use only. Totally impractical for cold email.
Zoho Mail (Workplace): Paid plans range 500–1,000/day depending on plan tier. ZeptoMail is a separate transactional service.
Yahoo Mail (Free): Aggressive spam filtering. High suspension risk for outbound bulk. Not recommended.
Amazon SES (Sandbox): Sandbox requires verified recipients. Request production access for unrestricted sending.
Amazon SES (Production): Highly scalable. Reputation-based. Bounce rate > 5% or complaints > 0.1% trigger throttling or suspension.
SendGrid (Free): Very limited free tier. Account verification can take days.
SendGrid (Essentials): Monthly quota, not daily. Reputation-based throttling. Dedicated IP available on Pro plans.
Cold Email Sending Best Practices
- ✓Stay below 50% of your daily limit. Sending at capacity signals bulk behavior to providers.
- ✓Warm new mailboxes for 14–21 days before reaching your target send volume. Start at 5–10 emails/day.
- ✓Use multiple mailboxes — spread volume across mailboxes instead of maxing out one.
- ✓Monitor delivery rates daily. A sudden drop in opens or increase in bounces means you hit a soft limit.
- ✓Use dedicated IPs — shared IPs pool risk from other senders. coldBirds' 1:1:1:3 isolation gives you a dedicated IP per 3 mailboxes.
Google Workspace limits you to 2,000 emails/day per user. With coldBirds' 1:1:1:3 isolation and automatic send scheduling, you stay safely within limits while maximizing delivery.
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