Updated October 26, 2026
· ~2 min read
All three deliver mail well when the domain is set up properly: SPF, DKIM and an aligned DMARC record, which Gmail and Outlook.com now require of bulk senders. They differ in price per message, how much tooling comes in the box, and how they keep marketing mail from hurting transactional mail.
Amazon SES is infrastructure: very cheap per message, inside your AWS account, with more left to you. Resend is built around a developer experience and a generous free tier. Postmark is built around transactional mail and keeps it on separate infrastructure from broadcasts.
Deliverability depends mostly on your domain and your behaviour: authenticated mail, a subdomain for marketing separate from the one for password resets, and stopping sends to addresses that bounce or complain. A provider cannot rescue a domain that mails people who never asked. Switching providers is a DNS change and an API swap, so start with whichever fits your stack and revisit at volume.
Question 1 of 3
Is the app on AWS, and is cost per message important?
**Amazon SES:** the lowest cost at any volume and the natural choice when the app already runs on AWS. You build or buy more around it: templates, a searchable log, suppression handling in your app. New accounts start in the SES sandbox and must request production access. **Resend:** the fastest to set up from a modern TypeScript stack, with a free tier that covers an early product. Per-message costs are several times SES at volume. **Postmark:** teams whose transactional mail is critical and who want it kept apart from marketing by the provider's own design. The highest per-message price of the three at low tiers.
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As of October 26, 2026. Provided as is, for general information, and accurate to the best of our knowledge on the date shown. Not legal, compliance, tax, financial or other professional advice. Prices, limits and vendor services change; check current vendor documentation before relying on anything here. Terms of use.