Send Rates & Limits
Send rate follows your connected email service. GoodPostal automatically paces large campaigns for reliable delivery. In practice, your sending service sets your real send speed.
The slower-of-two rule
Every send goes through two pacing factors in sequence:
- GoodPostal pacing. GoodPostal automatically paces large campaigns for reliable delivery, protecting multi-tenant fairness on our infrastructure.
- Your sending service's account rate, set by your email sending service based on plan tier, IP warmup, and sender reputation.
Send rate follows your connected email service. For most customers, the sending service is the limiting factor.
GoodPostal pacing
| Plan | Send rate | Monthly send capacity |
|---|---|---|
| GoodPostal / GoodPostal Nonprofit | Paced automatically for reliable delivery | No cap, metered at $0.05 per 1,000 from your first email |
| Trial (14 days) | Paced automatically for reliable delivery | 5,000 sends per month, a hard cap |
GoodPostal automatically paces large campaigns for reliable delivery, dispatching at a rate that follows your connected email service.
On the paid plans, sends are metered at $0.05 per 1,000, billed from your first email with no included allowance, and metering never pauses your campaigns. During the trial nothing is metered, but the 5,000-send monthly cap is enforced: a campaign that reaches it pauses and resumes at the start of the next monthly period, or as soon as you subscribe.
Sending service rate limits
Each email sending service sets its own per-account send limits. Below are the typical defaults; your specific account may differ based on plan tier and warmup status. Always check your sending service dashboard for the authoritative number.
| Sending Service | Tier | Typical rate |
|---|---|---|
| Amazon SES | Sandbox | 1 msg/sec (~3,600/hr), 200/day max |
| Amazon SES | Production (new) | ~14/sec (~50,000/hr) |
| Amazon SES | Production (warmed) | 50 to 500+/sec, scales with reputation |
| SendGrid | Free / Essentials | Low, varies by plan |
| SendGrid | Pro | ~600 req/min (~36,000/hr) |
| Mailgun | Foundation | 50,000 / month total |
| Mailgun | Scale+ | ~180,000/hr |
| Postmark | Paid plans | 5,000 concurrent (10 conn/IP) |
| SMTP2GO | Free / unverified | 25/hr if domain unverified |
| SMTP2GO | Paid (activated) | 200,000/hr account max |
What happens at the limit
When sends approach your sending service's limit, GoodPostal paces dispatch automatically:
- Campaign pacing. Large campaigns are dispatched evenly across the send window so the limiter never fully engages and your dashboard counter ticks smoothly.
- Sending service rate-limit handling. If your sending service returns a 429 (too many requests), GoodPostal backs off automatically (120s, then 300s, then 600s) and resumes when the service's window resets.
- Circuit breaker. If your sending service returns repeated errors (10 consecutive failures), the campaign is auto-paused and you're notified. Pending recipients are preserved and resume sending after the issue is fixed.
IP warmup considerations
If you're sending to a new sending service account or from a new dedicated IP, your sending service enforces warmup: lower volumes for the first few days, increasing gradually. During warmup, your service's effective rate may be far below its published max.
- SES Production (new): 200/day for the first 24 hours, scales up over weeks.
- Postmark Broadcast: 20,000/hr for the first 12 hours of bulk sending.
- Mailgun new accounts: Hourly throttle during account verification.
Check your sending service's warmup policy in their dashboard. During warmup, GoodPostal's pacing automatically respects the service's actual response rate.
How to send faster
Send rate follows your connected email service. So if you need to send faster than your current effective rate, the lever is your sending service:
- Upgrade your sending service plan
- Request a sending quota increase from your sending service
- Move to a sending service with higher limits. SMTP2GO Paid offers a high fixed hourly ceiling of 200,000/hour, and a warmed Amazon SES account can go higher still as its reputation grows.
If you have unusually high-volume sending needs, contact us; we can discuss enterprise arrangements.
Related docs
- Campaigns, creating and scheduling campaigns
- Sending Services Overview, connecting your email sending service
- Pricing, plan comparison