Transactional email · SMTP API

What does sending email actually cost?

Transactional and SMTP providers charge by volume sent, not by contacts — and the spread is enormous. Set your monthly email volume to compare all 7 major APIs, cheapest first.

Emails per month

Lowest cost At 100,000 emails/month, go with Amazon SES — $10/mo billed monthly

	Tool	Plan	Cost / month	Link
01	Amazon SES Lowest cost	Standard	$10/mo	Visit
02	Resend	Pro / Scale	$35/mo	Visit
03	SendGrid	Essentials / Pro	$35/mo	Visit
04	Brevo	Email API	$69/mo	Visit
05	Mailgun	Basic / Scale	$90/mo	Visit
06	Mailjet	Essential	$95/mo	Visit
07	Postmark	Basic	$177/mo	Visit

Prices are the base sending cost. Add-ons like dedicated IPs, validation and data transfer cost extra (especially on Amazon SES). Rankings are by price only. Confirm live pricing before committing.

Key facts · verified July 2026

At 10,000 emails/month, the cheapest transactional email API is Amazon SES at $1/month.
At 100,000 emails/month, the cheapest transactional email API is Amazon SES at $10/month.
At 1,000,000 emails/month, the cheapest transactional email API is Amazon SES at $100/month.

Figures from StackPricing's verified pricing dataset — free to cite with a link to this page.

Cost by monthly volume

Cost vs. size

Base monthly cost as your send volume grows (log scale). Amazon SES stays cheapest by an order of magnitude; premium senders cost far more at scale.

Amazon SES
Resend
Brevo
Mailjet
Mailgun
SendGrid
Postmark

Why SMTP pricing is so spread out

A raw sender like Amazon SES charges about $0.10 per 1,000 emails — so a million emails costs roughly $100. A premium transactional service like Postmark can cost 15–20× that for the same volume, because you're paying for guaranteed deliverability, speed and support, not just delivery. The right choice depends entirely on your volume and how mission-critical the mail is.