Prompt
I need email sending that scales without rate limit issues, what should I use?
Latest observation
Oct 5, 2026
OpenAI APIWeb search: off
If you need email sending that scales without rate-limit headaches, the usual answer is: use a transactional email service provider (ESP) with a proper sending infrastructure, not your own SMTP server.
Good options
- AWS SES — very scalable, low cost, strong choice if you’re already on AWS.
- SendGrid — easy to use, good APIs, solid for app emails.
- Mailgun — strong developer-focused option, flexible APIs.
- Postmark — excellent for transactional email deliverability and simplicity.
- SparkPost — also built for high-volume sending.
What to look for
- High sending limits / ability to request increases
- Dedicated IPs or IP pools if you send a lot
- Domain authentication: SPF, DKIM, DMARC
- Bounce/complaint handling
- Queueing and retry support
- Webhook/event tracking
- Good deliverability reputation
Best practical choice
- For very large scale and cost efficiency: AWS SES
- For developer convenience: SendGrid or Mailgun
- For best transactional deliverability: Postmark
Important note
Even with a good provider, you should still:
- queue emails
- rate-limit per provider guidance
- warm up new domains/IPs
- clean your recipient list
- separate transactional and marketing email
If you want, I can recommend the best provider based on your expected volume, budget, and whether it’s transactional or marketing email.