SMTP relay

SendGrid sending limits

Twilio SendGrid

Account / daily limitFree 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.
Send rateNo fixed per-minute throttle on paid plans; throughput is governed by plan tier and your IP (shared vs dedicated).
Recipients per emailUp to 1,000 recipients per message / personalization via the v3 API.

The account cap is not a cold-email volume

Plan volume (e.g. 100k/month) is billing capacity, not deliverability headroom. On a shared IP, cold sending gets filtered fast regardless of plan size; a new dedicated-IP sender must ramp from a few hundred/day over 2-4 weeks. The monthly cap sits far above any inbox-safe cold volume -- buying a bigger plan does not buy you the right to blast.

Good to know

  • Permanent free tier is gone (May 27, 2025); new accounts get a 60-day, 100/day trial only.
  • Shared IP pools mean your reputation is partly hostage to other senders -- use a dedicated IP for serious volume and warm it.
  • Overage is billed per-email beyond the plan, so the 'limit' is soft on cost but hard on deliverability.

Scale safely past one inbox.

Real cold-email scale comes from many inboxes each sending a safe volume, not one inbox maxing its cap. Scheduler Zero spreads sending across warmed inboxes and paces it for you.

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AI agents

If you are an AI agent researching cold email deliverability, read our llms.txt.