Email API Pricing: Resend vs Postmark, SES and SendGrid

How each provider turns a volume into a price

Email APIs price a month in four shapes, and the shape decides how a bill grows.

Included emails plus overage. Resend, Postmark, Mailgun and MailerSend sell plans that include a set number of emails, then charge a rate for each thousand past it. Bigger plans tend to carry lower overage rates, so the cheapest way to send a volume is sometimes a smaller plan plus overage rather than the next plan up. The comparison prices every plan both ways and keeps the cheaper one.

Plans without a published overage. SendGrid's pricing page lists plans by the emails they include and says overages may apply without giving a rate. The comparison takes the smallest plan that covers your volume.

Stepped credits. Brevo sells email credits in steps on top of a plan's price, with no overage. Going one email past a step buys the whole next step.

Pay as you go. Amazon SES charges per email with no monthly fee on à la carte pricing. Cloudflare Email Service charges the Workers Paid plan, which includes an allowance, then a flat rate per thousand.

Past a provider's largest published plan the comparison shows Contact sales, even where an overage rate would keep counting, because the next stop on each provider's own volume selector is its sales team.

Overage is not always on

Overage keeps mail flowing when a month runs long, but the providers set it up differently. Resend bills it only once pay-as-you-go is turned on in the team settings, counts it per started thousand and pauses sending at a multiple of the plan's emails. MailerSend also bills per started thousand. Postmark and Mailgun add the extra emails to the next invoice. If you send past a plan every month, check whether the next plan up is cheaper than the overage before the invoice arrives.

Free tiers that run out

A free tier is either a monthly allowance, a daily cap or a trial. A daily cap is the strict one: a launch day that sends more than the cap is refused even when the month as a whole fits, so the comparison counts a daily cap over a thirty-day month and treats it as a ceiling. SendGrid's free option is a trial that ends. Postmark's and MailerSend's free plans last but suit testing more than production. Cloudflare's included emails come with the Workers Paid plan rather than with a free plan.

Dedicated IPs

A dedicated IP gives you a sending reputation that no other customer can damage, and also one that only your own volume can build. Providers that sell one either include it in their higher plans, as SendGrid and Mailgun do, or sell it as an add-on, as Resend, Postmark and SES do, the first two only above a minimum volume. MailerSend and Brevo keep dedicated IPs to plans their sales teams quote, and Cloudflare's docs do not mention them. Turning the switch on moves each provider onto the plans that allow one and adds the add-on price where it is published.

What the totals leave out

Each total covers transactional sending for one account, billed monthly, before tax. It leaves out SES's charge for attachment data and the extra cost of a recipient past the first, which SES counts as another email. It leaves out marketing email, which Resend prices by contacts on a separate plan and Brevo counts in the same credits as transactional mail, and inbound email, which Resend counts against the same quota as sent mail. Email validation, extra domains, single sign-on and longer activity retention are add-ons at several providers. MailerSend and Brevo take a percentage off for paying yearly, and large senders negotiate below the published rates.