Best Transactional Email Services 2026: Email APIs and SMTP Relays Compared
We rank email sending APIs and SMTP relays for apps — the services that deliver password resets, receipts, sign-in codes and alerts — using only facts from their own sites: the price per 1,000 emails, the price of the cheapest paid plan with monthly billing, a permanent free plan and how many emails it allows per month, SMTP relay, a sending API, event webhooks, a dedicated IP, inbound email, how many days message logs are kept, whether your data can stay in the EU, a GDPR data processing agreement, SOC 2 and ISO/IEC 27001, an uptime SLA published as a document, the year the service started and a public status page. Every fact links to an official page with a check date. Newsletter and campaign tools are compared in a separate ranking. We do not test delivery speed or inbox placement ourselves and do not use reviews or user scores, and paid placements never change the Score.
| # | Company | Who it serves | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Bird Email (ex-SparkPost) | 79 | $0.40 | $15.00 | Yes | 1,000 | Yes | 30 days | Not verified | Free plan SMTP Dedicated IP Inbound |
| 2 | Mailtrap Email API/SMTP | 74 | $1.00 | $15.00 | Yes | 4,000 | Yes | 5 days | No | Free plan SMTP Dedicated IP Inbound |
| 3 | Brevo Transactional Email | 70 | Not verified | $9.00 | Yes | Not verified | Yes | Not verified | Yes | Free plan SMTP Dedicated IP Inbound EU data |
| 4 | Amazon SES | 68 | $0.16 | $0.00 | No | 0 | Yes | Not verified | Yes | SMTP Dedicated IP Inbound EU data |
| 5 | Resend | 66 | $0.90 | $20.00 | Yes | 3,000 | Yes | 30 days | No | Free plan SMTP Dedicated IP Inbound |
| 6 | MailerSend | 63 | $1.50 | $7.00 | Yes | 500 | Yes | 1 days | Yes | Free plan SMTP Dedicated IP Inbound EU data |
| 7 | Postmark | 63 | $1.80 | $15.00 | Yes | 100 | Yes | 45 days | No | Free plan SMTP Dedicated IP Inbound |
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- Price per 1,000 extra emails
- $0.40
- Cheapest paid plan, per month
- $15.00
- Permanent free plan
- Yes
- Free emails per month
- 1,000
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- 30 days
- Data kept in the EU
- Not verified
Pros
- Low price per 1,000 emails
- Permanent free plan
- SMTP relay
- Documented sending API
Details Visit site ↗ 87% backed by facts
-
- Price per 1,000 extra emails
- $1.00
- Cheapest paid plan, per month
- $15.00
- Permanent free plan
- Yes
- Free emails per month
- 4,000
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- 5 days
- Data kept in the EU
- No
Pros
- Permanent free plan
- Generous free allowance
- SMTP relay
- Documented sending API
Cons
- No EU data storage found
Details Visit site ↗ 96% backed by facts
-
- Price per 1,000 extra emails
- Not verified
- Cheapest paid plan, per month
- $9.00
- Permanent free plan
- Yes
- Free emails per month
- Not verified
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- Not verified
- Data kept in the EU
- Yes
Pros
- Cheap entry plan
- Data can stay in the EU
- Permanent free plan
- SMTP relay
Details Visit site ↗ 76% backed by facts
-
- Price per 1,000 extra emails
- $0.16
- Cheapest paid plan, per month
- $0.00
- Permanent free plan
- No
- Free emails per month
- 0
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- Not verified
- Data kept in the EU
- Yes
Pros
- Low price per 1,000 emails
- Cheap entry plan
- Data can stay in the EU
- SMTP relay
Cons
- No permanent free plan found
- Small or no free allowance
Details Visit site ↗ 82% backed by facts
-
- Price per 1,000 extra emails
- $0.90
- Cheapest paid plan, per month
- $20.00
- Permanent free plan
- Yes
- Free emails per month
- 3,000
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- 30 days
- Data kept in the EU
- No
Pros
- Permanent free plan
- Generous free allowance
- SMTP relay
- Documented sending API
Cons
- No EU data storage found
- No ISO/IEC 27001 certificate found
Details Visit site ↗ 96% backed by facts
-
- Price per 1,000 extra emails
- $1.50
- Cheapest paid plan, per month
- $7.00
- Permanent free plan
- Yes
- Free emails per month
- 500
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- 1 days
- Data kept in the EU
- Yes
Pros
- Cheap entry plan
- Data can stay in the EU
- Permanent free plan
- SMTP relay
Details Visit site ↗ 78% backed by facts
-
- Price per 1,000 extra emails
- $1.80
- Cheapest paid plan, per month
- $15.00
- Permanent free plan
- Yes
- Free emails per month
- 100
- Dedicated IP
- Yes
- Log retention on the cheapest paid plan
- 45 days
- Data kept in the EU
- No
Pros
- Permanent free plan
- SMTP relay
- Documented sending API
- Delivery and bounce events by webhook
Cons
- High or unpublished price per 1,000 emails
- No EU data storage found
Details Visit site ↗ 88% backed by facts
Not ranked yet: not enough verified data
These services are known to us, but we haven't verified enough facts to rank them fairly.
- Elastic Email API (69% backed by facts)
- Loops (64% backed by facts)
- Mailchimp Transactional (ex-Mandrill) (57% backed by facts)
- Mailgun (site closed to automated checks, )
- Mailjet (site closed to automated checks, )
- SMTP2GO (68% backed by facts)
- SendPulse SMTP (44% backed by facts)
- Twilio SendGrid (68% backed by facts)
Sites marked as closed refuse automated reading (403 error, captcha or a robots.txt ban). We don't bypass such protection, so we can't verify their facts and they are not ranked. This says nothing about their quality. A company can send links to its official pages to [email protected].
How we calculate the Score
30%
Price
The price in US dollars of 1,000 emails sent beyond the volume of the cheapest paid plan, or the pay-as-you-go rate per 1,000 emails, exactly as written on the official pricing page: $0 scores 100, $2 or more scores 0 (weight 2). A rate given per email is converted to 1,000 emails; we never divide a plan fee or a block price by the emails it includes. Also the price of the cheapest paid plan with monthly billing (or the fixed monthly deposit): $0 when the service is pure pay-as-you-go, $50 or more scores 0 (weight 2). A permanent free plan adds weight 1; a trial that ends does not count. The number of emails per month on that free plan adds weight 1 (log scale, 10,000 or more scores 100; 0 when there is only a trial; a limit stated only per day is not converted). Prices shown only in a currency chosen by our visitor location, only for annual billing or only after a script runs are left empty.
30%
Sending features
Whether you can send through an SMTP relay (weight 1) and through a documented API (weight 1), receive delivery, bounce and complaint events pushed to your own URL by webhooks or a push notification service (weight 1), get a dedicated IP address on some plan or as a paid add-on (weight 1), and receive inbound email into your app (weight 1). Also how many days the logs or copies of sent messages are kept on the cheapest paid plan (weight 1, log scale, 30 days or more scores 100). Beta and preview features do not count. A feature fact shows that the feature exists, not that the cheapest plan has it: check the note under each fact.
25%
Data protection and reliability
Whether your account and message data can be kept in the European Union — the vendor stores it there or lets you choose an EU region for storage, not only for sending (weight 2); a GDPR data processing agreement (weight 1); a SOC 2 report (weight 1) and ISO/IEC 27001 certification (weight 1) for the vendor's own service, not only its data center; and the monthly uptime in a published SLA document or in the terms of service: 99% scores 0, 100% scores 100 (weight 1). Uptime figures from marketing pages or plan tables are not an SLA. We record the vendor's statement; we do not audit it.
15%
Track record
How long the service or company has been running: 20 years or more scores 100 (weight 2), and whether it publishes a public status page with incidents (weight 1).
How to choose a transactional email service
Price your real volume
Take your monthly emails, add the plan fee and the price of every extra 1,000, and compare at least two volumes. Some plans are cheap at the bottom and expensive in the middle.
Check what the free plan really allows
Look at the daily cap, the number of sending domains and how long logs are kept. A free plan that keeps logs for one day makes debugging delivery problems hard.
Set up SPF, DKIM and DMARC first
Authenticate your sending domain before the first real email. Gmail and Yahoo reject or filter bulk mail without it, and every service in this ranking walks you through the DNS records.
Wire up bounces and complaints
Use webhooks to stop sending to addresses that bounce or mark you as spam. Ignoring them is the fastest way to damage your sender reputation.
Frequently asked questions
Which transactional email service is best?
The service in first place has the highest Score under our open method, but the Score does not measure inbox placement or how well a tool fits your stack. Low-volume apps usually care most about the free plan and the entry price; high-volume senders care about the price per 1,000 emails and a dedicated IP.
What is the difference between transactional email and email marketing?
Transactional emails are triggered by something a user did — a sign-up, a password reset, an order — and go to one person at a time through an API or SMTP. Newsletters and campaigns go to a list. Many vendors sell both, but price them differently; this ranking compares the transactional side, and campaign tools have their own ranking.
Why is the price per 1,000 emails empty for some services?
Some vendors sell blocks of emails or volume steps without a per-1,000 rate, some show prices only in the currency of our visitor location, and some fill the page in with a script. We do not divide a plan fee by its emails, so the fact stays empty and the plan price is compared instead.
Do I need a dedicated IP?
Usually not below a few hundred thousand emails a month. A dedicated IP needs steady volume to keep a good reputation; at low volume a well-managed shared pool often delivers better. Most vendors offer one only on higher plans or as a paid add-on.
What does an empty fact mean?
We could not confirm it on an official page, sometimes because the vendor's site refused automated access. An empty fact scores zero and lowers data completeness. A service with too little data is not ranked.