Best Transactional Email Services: Resend vs Postmark vs Amazon SES vs Mailgun vs SendGrid
Free tiers, entry prices, inbound email, dedicated IPs, log retention and EU options checked on each vendor's site - five email APIs side by side.
Best overall: Resend
Resend is our pick for most developers: 3,000 free emails a month, $20 for 50,000, inbound email, webhooks and SMTP on every plan, 30-day logs and a choice of sending regions including Ireland. Postmark is the choice if you want transactional and broadcast mail on separate infrastructure and longer log retention, Amazon SES is the lowest-cost option at high volume if you can handle AWS setup, Mailgun suits teams that need data hosted in the EU, and SendGrid fits teams that want its Marketing Campaigns product next to the email API.
Side-by-side comparison
Every tool scored on the same criteria. Hover a column to focus it, or show only the rows where they differ.
| 5 tools compared | ★ Our pick Resend | Postmark | Amazon SES | Mailgun | SendGrid | Ad space Your tool here |
|---|---|---|---|---|---|---|
| Our score | 9.2 | 9.0 | 8.7 | 8.5 | 8.0 | Get your tool into this table Shown next to the top 5 transactional email tools, labeled as sponsored. Advertise here $149/mo |
| Starting price | Free / $20 /mo (50,000 emails) | Free / $15 /mo (10,000 emails) | $0.16 /1,000 emails (Essentials) | Free / $15 /mo (10,000 emails) | From $19.95 /mo | |
| Best for | Developers & startups | Product teams that want long logs | High volume on AWS | Teams that need EU data hosting | Email API plus marketing campaigns | |
| Free tier | 3,000/mo (100/day) | 100/mo, no expiry | 12-month free tier | 100/day | 60-day trial (100/day) | |
| Extra emails (per 1,000) | $0.90 (Pro) | $1.20 - $1.80 | $0.16 (Essentials) | $1.10 - $1.80 | - | |
| SMTP relay | ||||||
| Inbound email | All plans | Pro and above | $0.10 per 1,000 + data | All plans (routes) | Inbound Parse | |
| Dedicated IP | $30/mo on Scale | $50/mo, 300k+/mo | $24.95/mo | $59/mo add-on | Included on Pro | |
| Log retention | 30 days | 45 days (up to 365) | - | 1 - 30 days | - | |
| EU option | Ireland sending region | No (US only) | - | EU hosting | EU data residency listed | |
| Marketing / broadcast emails | Separate plans (1,000 contacts free) | Broadcast streams | - | Separate product from $15/mo | ||
| Visit site | Visit site | Visit site | Visit site | Visit site |
Prices and features were checked on each vendor's official website on Nov 11, 2026. Prices are in USD as shown there; promotions, taxes and regional pricing can change them. Where we could not confirm a detail on the vendor's own site, we show "-" instead of guessing. Our scores are editorial judgments.
Detailed reviews
What each tool does best, where it falls short, and who should pick it.
1. Resend
Modern email API built for developers
Resend's free plan sends 3,000 emails a month (100 a day) from up to 3 domains, and Pro is $20 a month for 50,000 emails with extra emails at $0.90 per 1,000. Every plan includes the REST API, SMTP relay, official SDKs, inbound email, signed webhooks and React Email templates. You can send from North Virginia, Ireland, Sao Paulo or Tokyo, and email data is kept for 30 days on all plans.
+ Pros
- 3,000 free emails a month from up to 3 domains
- Inbound email, webhooks and SMTP on every plan, including Free
- Send from the US, Ireland, Brazil or Japan
- React Email templates and SDKs for 10+ languages
- Cons
- Free plan capped at 100 emails a day
- Choosing Ireland sets where mail is sent from; account data is still stored in the US
- Dedicated IPs ($30/mo) need the Scale plan and 3,000+ emails a day
2. Postmark
Transactional email with separate broadcast streams
Postmark's free plan includes 100 emails a month and does not expire. Paid plans start at 10,000 emails a month: Basic $15, Pro $16.50 and Platform $18, with extra emails from $1.80 down to $1.20 per 1,000. Transactional and broadcast streams run on separate infrastructure, activity is kept for 45 days by default (up to 365 days on Pro and above), and Pro adds inbound email processing.
+ Pros
- Free plan never expires
- Transactional and broadcast mail never share IP ranges
- 45-day activity history, up to 365 days on Pro and above
- Official libraries for Node.js, Python, Ruby, PHP, .NET, Java and more
- Cons
- Free plan is only 100 emails a month, and there's no tier between 100 and 10,000
- Inbound processing and dedicated IPs only on Pro and above
- Hosted in the US with no EU data hosting planned
3. Amazon SES
Pay-per-email sending on AWS
Amazon SES charges per email instead of a monthly plan. New accounts start on the Essentials plan at $0.16 per 1,000 emails, and the a la carte rate for outbound email is $0.10 per 1,000 plus $0.12 per GB of attachments. You can send through the API, SMTP or an AWS SDK, receive inbound email, and add standard dedicated IPs at $24.95 a month each. New accounts begin in a sandbox limited to verified recipients and 200 messages a day until you request production access.
+ Pros
- Pay per email instead of a monthly plan
- Standard dedicated IPs at $24.95 a month
- Virtual Deliverability Manager included in the Essentials, Pro and Enterprise plans
- Cons
- New accounts start in a sandbox (verified recipients only, 200 messages a day)
- More setup than the other services (AWS account, regions, notifications)
- Pricing has several parts: plans, attachments, inbound chunks, notifications
4. Mailgun
Email API with US and EU hosting
Mailgun's free plan sends 100 emails a day from 1 custom domain. Basic is $15 a month for 10,000 emails, Foundation $35 for 50,000 and Scale $90 for 100,000, with extra emails from $1.80 down to $1.10 per 1,000. Every plan has the REST API, SMTP relay, webhooks and inbound routes, and you can host your data in the US or the EU. Log retention runs from 1 day on Free and Basic to 30 days on Scale.
+ Pros
- Choose US or EU hosting so data stays in that region
- Inbound routes on every plan, including Free
- Email validation available as an add-on (5,000 included on Scale)
- SDKs for Go, Node.js, PHP, Java, Ruby and Python
- Cons
- Only 1 day of logs on Free and Basic
- Free and Basic allow 1 custom sending domain
- Template builder starts on the Foundation plan
5. SendGrid
Twilio's email API and marketing suite
Twilio SendGrid's Email API has a 60-day free trial at 100 emails a day, then paid plans: Essentials from $19.95 a month and Pro from $89.95 a month, which includes a dedicated IP. You get SMTP relay, the Web API, official SDKs for seven languages, the Inbound Parse webhook, event webhooks and dynamic templates. Marketing Campaigns is a separate product with its own plans from $15 a month.
+ Pros
- Dedicated IP included on Pro and Premier
- Inbound Parse webhook and dynamic templates
- Marketing Campaigns available under the same login
- Cons
- Free option is a 60-day trial, not a permanent free plan
- Searchable activity history is short (days, not weeks)
- Included email volume depends on the tier you pick on the pricing page
How we compared
We checked every price, plan and feature in this article on each vendor’s own website on November 11, 2026. Prices are in USD per month as listed there. Where a vendor’s site did not confirm a detail - for example SES log retention or which SendGrid plans include EU data residency - the table shows ”-”. The scores are our editorial judgment, weighted toward value, features included on entry plans and ease of setup.
Disclosure: RankJury sends its own contact-form emails through Resend. That did not change the scores, which are based on the published facts above.
How to choose a transactional email service
- Volume and price per email. Monthly plans (Resend, Postmark, Mailgun, SendGrid) are simplest; Amazon SES’s per-email pricing wins at high volume.
- Free tier for testing. Check daily limits, not just monthly ones - several free plans cap you at 100 emails a day.
- Logs and debugging. Retention ranges from 1 day (Mailgun Free and Basic) to 45 days by default at Postmark. Longer logs make support tickets easier.
- Inbound email. If users reply to your emails or you parse incoming mail, check which plans include inbound processing.
- Dedicated IPs. Only worth it at steady high volume; most providers require a minimum (for example Postmark asks for 300,000 emails a month, Resend for more than 3,000 a day).
- Data location. If your users are in the EU, decide whether you need EU data hosting (Mailgun) or just EU sending (Resend).
Other tools worth a look Sponsored
Frequently asked questions
What is a transactional email service?
It's an email API or SMTP service your app uses to send one-to-one messages triggered by a user action - password resets, sign-up confirmations, receipts, notifications. They're built for fast, reliable delivery and give you logs, bounce handling and webhooks.
Which transactional email service has the best free plan?
Of the five, Resend's free plan is the largest at 3,000 emails a month (100 a day). Mailgun allows 100 emails a day and Postmark 100 a month that never expire. SendGrid offers a 60-day trial, and Amazon SES has a 12-month free tier for new AWS accounts.
Which is cheapest at high volume?
Amazon SES, which charges per email: $0.16 per 1,000 on the Essentials plan new accounts start on, or $0.10 per 1,000 on the a la carte rate. The trade-off is more setup and a sandbox you must leave before sending to real users.
Which services offer an EU option?
Mailgun lets you host your data in the EU. Resend can send from Ireland (eu-west-1), but says account data is stored in the US. SendGrid lists EU data residency among its features. Postmark is hosted in the US and has no plans for EU servers.
Can these services receive email too?
Yes. Resend includes inbound email on every plan, Mailgun includes inbound routes on every plan, Postmark offers inbound processing on Pro and above, SendGrid has the Inbound Parse webhook, and Amazon SES charges per 1,000 inbound emails plus data.
Prices and features were checked on Nov 11, 2026 and can change at any time. Some links may be affiliate links; this never affects our scores. Placements marked “Sponsored” are paid and are never ranked or scored. Products marked “Paid inclusion” were added at the vendor's request and scored like every other product. How we make money →