# Best Transactional Email Services in 2026 > The best transactional email services in 2026 compared: Cresca, Resend, Postmark, SendGrid, Mailgun, Amazon SES and more, by price, free tier and features. Canonical: https://www.cresca.xyz/blog/best-transactional-email-services Author: Lalit Kumar Jangid Published: 2026-10-27 Last updated: 2026-10-27 The **best transactional email services** all deliver password resets, receipts and alerts reliably. Where they differ is everything around the send: the free tier, the price at your volume, SMTP and webhooks, templates, and whether your marketing email can live in the same account. This guide compares nine transactional email services side by side, using each vendor's own pricing and product pages, checked on October 27, 2026. *We make Cresca, so it is listed first. Every other entry is described from the vendor's own public pages, without ranking claims about them. Prices and plans change, so confirm on each vendor's site before you buy.* **TL;DR** - Cresca: a transactional email API and AI-designed marketing campaigns on one plan, from $29/month. - Most services price API email by monthly volume and sell marketing email as a separate plan or product. - Every service here supports your own verified domain with SPF and DKIM, which matters more for deliverability than the provider you pick. - Check SMTP, webhooks, free-tier limits and how marketing email is billed before you commit. ## What is a transactional email service? A transactional email service sends the one-to-one emails your application triggers: sign-up confirmations, password resets, receipts, invoices, shipping updates and security alerts. You call it from your code through an HTTP API or SMTP, and it handles authentication, delivery, retries, bounces and suppression. Unlike marketing email, these messages are expected and time-sensitive, so a good service delivers them within seconds and keeps them separate from bulk campaigns. ## Best transactional email services compared (2026) | Service | Best for | Free option | Paid from | SMTP relay | Webhooks | Marketing email | | --- | --- | --- | --- | --- | --- | --- | | **Cresca** | App email and AI-designed marketing campaigns in one account | 30 days free, 50 emails, no credit card | $29/month: 7,500 emails and 5,000 contacts, campaigns included | On the roadmap | On the roadmap | Yes, on the same plan | | **Resend** | Developers; sends emails built with React Email | Free plan: 3,000 emails/month, 100 per day | $20/month for 50,000 emails | Yes | Yes | Separate marketing plans priced by contacts | | **Postmark** | Transactional email with separate message streams | 100 emails/month developer plan | $15/month for 10,000 emails | Yes | Yes | Broadcast message streams | | **SendGrid** | Email API at scale, part of Twilio | 60-day free trial, 100 emails/day | Essentials from $19.95/month | Yes | Yes | Marketing Campaigns, sold as a separate plan | | **Mailgun** | Developers; email API, SMTP and email validation | Free plan: 100 emails/day | $15/month for 10,000 emails | Yes | Yes | Not stated on its pricing page | | **Amazon SES** | High-volume sending from AWS applications | Up to $200 in AWS Free Tier credits for new AWS customers | Pay as you go, per 1,000 emails | Yes | Event publishing (SNS, EventBridge and more) | Sends marketing email; no campaign builder stated | | **MailerSend** | Email, SMS and WhatsApp for apps | Free plan: 500 emails/month | $7/month for 5,000 emails | Yes | Yes | Not stated; bulk emailing on paid plans | | **Mailtrap** | Developer and product teams; sending plus a testing sandbox | Free plan: 4,000 emails/month, 150 per day | $15/month for 10,000 emails | Yes | Yes | Email Marketing, sold separately | | **Mailchimp Transactional** | Mailchimp customers adding app email | Up to 500 free sends to a verified domain | $20 per block of 25,000 emails, plus a Mailchimp Standard or Premium plan | Yes | Yes | Yes, through the Mailchimp plan it is added to | *Based on each vendor's public pricing and product pages, checked on October 27, 2026. Prices are in US dollars, billed monthly where both options are shown.* ## How we compared these services - **Sending:** an HTTP API, SMTP relay, batch sending and scheduling. - **Reliability features:** idempotent retries, clear error responses and delivery events. - **Templates:** whether templates live in the service with variables and versions, or in your code. - **Pricing:** the free option and the first paid plan, as listed by the vendor. - **Marketing email:** whether newsletters and campaigns run in the same account and on the same bill. ## 1\. Cresca: transactional email and AI marketing on one plan Cresca is a transactional email service and an AI email marketing platform in one account. Your app sends password resets and receipts through a REST API, and your team designs on-brand campaigns from a short brief with an AI agent, all from the same verified domain and on the same plan. See [Cresca transactional email](https://www.cresca.xyz/transactional-email). - **API:** `POST /emails` for one email to up to 50 recipients, batches of up to 100 emails per request, scheduling up to 30 days ahead, attachments and tags. `Idempotency-Key` headers make retries safe, so a timeout never sends a receipt twice. - **Templates:** A template editor with variables, test emails and version history. Your app sends the alias and the values; sends always use the published version. - **Marketing:** AI-designed campaigns with 36 templates, a design editor, contact lists, scheduling and campaign reports, on the same plan as API email. - **Pricing:** 30 days free with 50 emails and no credit card. Professional is $29/month for 7,500 emails and 5,000 contacts; API email and campaigns share the allowance. - **On the roadmap:** Outbound webhooks and an SMTP relay. Today you read each email's status from the API or the dashboard timeline. - **Start:** The [quickstart](https://www.cresca.xyz/docs/quickstart) and tutorials for [Node.js](https://www.cresca.xyz/blog/send-email-nodejs), [Python](https://www.cresca.xyz/blog/send-email-python), [PHP](https://www.cresca.xyz/blog/send-email-php) and [Go](https://www.cresca.xyz/blog/send-email-golang). ## 2\. Resend Resend presents itself as an email API for developers and highlights sending emails written with React Email, TypeScript and Tailwind. - **Free option:** A free plan with 3,000 emails per month, limited to 100 per day. - **Paid:** Pro is $20/month for 50,000 emails. - **Sending:** REST API, SMTP relay, official SDKs and webhook endpoints on all plans. - **Marketing:** Marketing plans are separate and priced by contacts. ## 3\. Postmark Postmark describes itself as a transactional email service and separates transactional and broadcast email into message streams on separate sending infrastructure. - **Free option:** A developer plan with 100 emails per month that does not expire. - **Paid:** Basic is $15/month for 10,000 emails. - **Sending:** Email API, SMTP, event webhooks and inbound email processing. - **Marketing:** Broadcast message streams for bulk email in the same account. ## 4\. SendGrid SendGrid, part of Twilio, offers the Twilio SendGrid Email API and a separate Marketing Campaigns product. - **Free option:** A 60-day free trial with 100 emails per day. - **Paid:** Email API Essentials starts at $19.95/month. - **Sending:** API and SMTP, with event webhooks on paid plans. - **Marketing:** Marketing Campaigns is purchased as a separate plan. ## 5\. Mailgun Mailgun calls itself a transactional email delivery service and API for developers, with separate products for sending, deliverability, email validation and inspection. - **Free option:** A free plan with 100 emails per day. - **Paid:** Basic starts at $15/month for 10,000 emails. - **Sending:** RESTful APIs and SMTP relay, with tracking, analytics and webhooks. - **Marketing:** Not stated on its pricing page. ## 6\. Amazon SES Amazon Simple Email Service sends transactional, marketing and bulk email from applications with pay-as-you-go pricing, inside AWS. - **Free option:** New AWS customers receive up to $200 in AWS Free Tier credits that can be applied to SES. - **Paid:** Priced per 1,000 emails: new accounts start on the Essentials plan at $0.16 per 1,000 emails, and Pro and Enterprise plans add fixed monthly charges. - **Sending:** SES API, SMTP interface and AWS SDKs. Sending events can be published to Amazon SNS, EventBridge, CloudWatch and Data Firehose. - **Marketing:** Sends marketing and newsletter email; no campaign builder is described on its pages. ## 7\. MailerSend MailerSend presents itself as a team-friendly email API for modern apps, sending transactional email, SMS and WhatsApp messages. - **Free option:** A free plan with 500 emails per month. - **Paid:** Hobby is $7/month for 5,000 emails. - **Sending:** Email API and SMTP relay, with webhooks for email and SMS events. - **Marketing:** No separate marketing product is described; paid plans include bulk emailing. ## 8\. Mailtrap Mailtrap describes modern email delivery for developer and product teams, with separate products for email sending, email marketing and a testing sandbox. - **Free option:** Email API/SMTP free plan with 4,000 emails per month, up to 150 per day. - **Paid:** Basic is $15/month for 10,000 emails. - **Sending:** API and SMTP relay, with webhooks for delivery and engagement events. - **Marketing:** Email Marketing is a separate product with its own plans. ## 9\. Mailchimp Transactional (formerly Mandrill) Mailchimp Transactional is Mailchimp's transactional email service, renamed from Mandrill in 2025, and is sold as an add-on to a Mailchimp plan. - **Free option:** New users can send up to 500 free emails to their verified domain. - **Paid:** $20 per block of 25,000 emails, added to a Mailchimp Standard or Premium plan. - **Sending:** Transactional API and SMTP integration, with webhooks for message events. - **Marketing:** Campaigns come from the Mailchimp plan the add-on is attached to. ## How to choose a transactional email service 1. **Map what your app sends.** List each email, its trigger and how quickly it must arrive. Password resets and sign-in codes need seconds; digests can wait. See [transactional vs marketing email](https://www.cresca.xyz/blog/transactional-vs-marketing-email). 2. **Decide between API and SMTP.** If you write the sending code, an API gives you clearer errors and safe retries; if a tool only has SMTP settings, you need SMTP. See [SMTP vs API](https://www.cresca.xyz/blog/smtp-vs-api-sending). 3. **Check retries and errors.** Look for idempotency keys, documented error names and rate limits, so a timeout never becomes a duplicate receipt. 4. **Price your real volume.** Compare the plan that covers your monthly emails, not only the free tier, and include overage rates. 5. **Decide where marketing email lives.** One account for app email and campaigns means one domain setup, one contact list and one bill; separate products mean two of each. 6. **Authenticate your domain.** SPF, DKIM and DMARC decide inbox placement far more than the provider does. See the [Gmail and Yahoo sender requirements](https://www.cresca.xyz/blog/gmail-yahoo-sender-requirements). ## Moving your transactional email to Cresca Verify your sending domain in Cresca, add a sender, create a sending-access API key and switch one email type at a time, starting with something low-risk like a welcome email. Keep the old provider running until the new sends look right in the dashboard timeline. Leaving Amazon Pinpoint before its end of support? Read the [Amazon Pinpoint alternative](https://www.cresca.xyz/blog/amazon-pinpoint-alternative) guide. For every field of the Emails API, see the [send email API guide](https://www.cresca.xyz/blog/send-email-api). ## Frequently asked questions ### What is the best transactional email service? It depends on what else you send. If your team also sends newsletters and campaigns, Cresca puts a transactional email API and AI-designed marketing email on one plan and one verified domain. Services such as Resend, Postmark, SendGrid, Mailgun, Amazon SES, MailerSend, Mailtrap and Mailchimp Transactional focus on sending, and most bill marketing email separately. ### What is the difference between transactional and marketing email? Transactional email is triggered by a person's action or account event, such as a password reset or receipt, and is expected by the recipient. Marketing email is sent to a list to promote something and needs consent and an unsubscribe link. Keeping them on separate sending streams or subdomains protects the reputation of your critical emails. ### Do I need a separate service for marketing email? Not with Cresca: API email and AI-designed campaigns run in one account on one plan. With most transactional email services, marketing email is a separate product or plan with its own pricing. ### Does the transactional email provider affect deliverability? Less than most people expect. Inbox placement depends mainly on SPF, DKIM and DMARC for your own domain, your sending reputation, complaint and bounce rates, and your content. A good provider helps by handling bounces, suppression and authentication correctly. ### Is there a free transactional email service? Most services in this comparison have a free plan or a free trial with daily or monthly limits; the table above lists each one as published by the vendor. Cresca is free for 30 days with 50 emails and no credit card, which is enough to build and test an integration. ## Try Cresca Send your app's email and your campaigns from one account. **[Try Cresca free for 30 days](https://app.cresca.xyz/signup)**, no credit card required, then follow the [quickstart](https://www.cresca.xyz/docs/quickstart).