Email Sending Cost Checklist Before You Pick an ESP

Use this before you paste a number into a pitch deck. Then run the Email Cost Calculator at the same volume.

Volume

• Count recipients if you might use SES (one MIME with two To: lines is two SES sends).
• Count messages against ESP included quota the way the vendor bills.
• Separate transactional from marketing. Marketing is a different pricing model.

SKU honesty

• If the vendor has a monthly floor, quote the floor — not overage × volume.
• Drop Free plans with a daily cap that cannot cover the month.
• Pick the cheapest SKU that can send (Postmark Platform can beat Pro).

Vendor-specific gotchas

• SES: free allowance off unless Cost Explorer shows it. No silent 62k EC2.
• Cloudflare: Workers Paid required for public send; $5 unless you already pay it; verified destinations $0.
• SendGrid: trial ≠ production.
• Resend: 100/day Free cap.

Hygiene (you still pay for bad addresses)

• Validate format, flag throwaways, and dedupe before the first paid month.

After you have a number

• Re-check the vendor pricing page (Tools.Town rates are dated, not live).
• Add dedicated IPs / VDM / inbound Worker CPU only if you actually use them — they are out of v1.

Agency shape: Quote transactional email for a SaaS client.