Buyer’s guide · Technology
Best Transactional Email Software in 2026: Pricing & Comparison
Five transactional email vendors compared on published free quotas, entry price and overage, checked 6 October 2026.
- Product teams wanting the largest free month: Resend — 3,000 emails a month on the free plan, then Pro at $20.
- Teams wanting a $15 entry plan: Mailgun Basic or Postmark Basic — both list $15 for 10,000 emails.
- Existing Twilio accounts: Twilio SendGrid — 100 emails a day free, paid plans from $19.95.
- AWS accounts: Amazon SES — à la carte outbound at $0.10 per 1,000 emails.
Transactional email software is an API or SMTP relay for application-triggered mail such as receipts, password resets and alerts. It is not a newsletter tool, even when the vendor also sells broadcasts.
Every company uses the same fields: published pricing, free plan or trial, core focus and the main limitation. The order is not a quality ranking. Public $0 / published price first, quote-led last.
Compared at a glance
| Platform | Pricing | Best for | Link |
|---|---|---|---|
| 1. Resend | Free $0 for 3,000 emails/month (100/day cap). Pro $20/month for 50,000. Scale from $90/month. | A product team that wants a free quota and a React-friendly API | Site → |
| 2. Mailgun | Free $0, 100 emails/day. Basic from $15/month for 10,000. Foundation is free for 1 month, then $35/month for 50,000. | A team that wants SMTP plus API and a published volume ladder | Site → |
| 3. Twilio SendGrid | Free start, 100 emails/day. Paid plans start at $19.95/month. Included paid volume not on the hub page. | A team already on Twilio | Site → |
| 4. Postmark | Free $0 for 100 emails/month. Basic $15, Pro $16.50, Platform $18, each for 10,000, then overage. | Low-volume transactional senders | Site → |
| 5. Amazon SES | À la carte outbound $0.10 per 1,000. Essentials $0.16 per 1,000 for the first 10 million. Pro adds $105/month. | AWS users who want usage pricing | Site → |
Prices checked on 6 October 2026 from resend.com/pricing.md, mailgun.com/pricing, the Twilio pricing hub, postmarkapp.com/pricing and aws.amazon.com/ses/pricing. Confirm live pages before you buy.
How the market splits
Resend, Mailgun, Postmark and SendGrid sell a monthly plan with included volume and an overage. Amazon SES sells the message, then optional plans that add a monthly fee. Broadcast email is a different meter. Dedicated IPs and validation sit outside the entry price.
The 5 companies in detail
Resend
Largest published free monthly quota
Best for: developers who want a simple email API and 3,000 free emails a month before Pro.
| Attribute | Resend |
|---|---|
| Published pricing | Free $0 / 3,000 emails a month, 100 a day. Pro $20/month for 50,000. Scale from $90/month. |
| Free plan or trial | Free plan. No annual discount. Paid overage is optional. |
| Core focus | Transactional API, SMTP, inbound, React Email. Broadcasts are priced by contacts. |
| Main limitation | Free plan stops at 100 emails a day. SSO is a Scale add-on at $150/month. |
- Pro is $20/month for 50,000 emails, then $0.90 per extra 1,000.
- Broadcasts do not count against the transactional quota.
- Dedicated IPs are $30/month on Scale after 3,000 emails a day.
Mailgun
Published ladder from a daily free cap
Best for: teams that want both an API and SMTP, plus inbound routing, on a named monthly plan.
| Attribute | Mailgun |
|---|---|
| Published pricing | Free $0, 100 emails/day. Basic from $15/month for 10,000. Foundation is free for 1 month, then $35/month for 50,000. Scale $90/month for 100,000. |
| Free plan or trial | Free plan. Foundation and Scale show a one-month trial, then the listed price. |
| Core focus | Transactional and bulk send, validations as an add-on, EU or US region. |
| Main limitation | Free and Basic keep 1-day log retention on the page we loaded. |
- Basic overage starts at $1.80 per 1,000 emails.
- Foundation lists 1,000 custom sending domains and 5-day log retention.
- Extra dedicated IPs were listed at $59 per IP per month in the pricing FAQ.
Twilio SendGrid
Free daily cap on the Twilio hub
Best for: companies that already buy Twilio SMS, Verify or voice and want email on the same account.
| Attribute | Twilio SendGrid |
|---|---|
| Published pricing | Free with 100 emails/day. Paid plans start at $19.95/month on the Twilio pricing hub. |
| Free plan or trial | Free start. The hub says no credit card is required to start a Twilio account. |
| Core focus | Email API and SMTP. Marketing Campaigns are a separate product. |
| Main limitation | The hub page did not list included volume on the $19.95 plan. |
- Paid SendGrid Email API plans start at $19.95/month on the Twilio hub, checked 6 October 2026.
- The same page lists a free start of 100 emails a day.
- SendGrid’s own pricing URL now points buyers to Twilio, so included volume must be confirmed on the live plan.
Postmark
Small free plan, then a tight overage
Best for: apps that send password resets and receipts and want activity retention.
| Attribute | Postmark |
|---|---|
| Published pricing | Free $0 for 100 emails/month. Basic $15, Pro $16.50, Platform $18, each for 10,000 emails, then overage. |
| Free plan or trial | Developer plan does not expire. No overage on the free plan. |
| Core focus | Transactional streams, inbound parsing, templates. |
| Main limitation | Free plan is 100 emails a month, not a day. |
- Basic extra email is $1.80 per 1,000. Platform extra is $1.20 per 1,000.
- Default activity retention on paid plans is 45 days.
- Dedicated IPs start at $50/month and need Pro plus 300,000 emails a month.
Amazon SES
Usage price, no platform minimum on à la carte
Best for: AWS accounts that want outbound email billed per thousand messages.
| Attribute | Amazon SES |
|---|---|
| Published pricing | À la carte outbound $0.10/1,000. Essentials $0.16/1,000 for 0–10 million. Pro $0.22/1,000 plus $105/month per account per region. |
| Free plan or trial | No monthly free email quota was stated on the pricing page. |
| Core focus | API and SMTP send, plus Mail Manager inbound options. |
| Main limitation | Attachment data is extra at $0.12/GB. |
- Tiered Essentials rates apply only inside each volume band.
- A page example: 250,000 Essentials emails at 32KB cost $40.96 including attachment data.
- New account-region combinations with no metered activity since 1 June 2025 start on Essentials from 21 July 2026, per the pricing page.
Kurums Match
We want the largest free monthly quota3,000 emails before a paid plan
We want a $15 plan with 10,000 emailsMailgun or Postmark
Mailgun Basic and Postmark Basic both list $15 for 10,000. Mailgun’s free plan is 100 a day. Postmark’s is 100 a month.
We already pay TwilioEmail on the same account
Twilio SendGrid: 100 emails a day free, paid plans from $19.95/month. Confirm included volume on the live plan.
We want AWS usage pricingNo platform minimum
Amazon SES à la carte is $0.10 per 1,000 outbound emails, plus attachment data.
Buying tip
Price a realistic month, not the entry plan. A 50,000-email month is inside Resend Pro at $20 and Mailgun Foundation at $35, and far above Postmark Basic once overage starts.
FAQ
Does the free plan include a custom domain?
Are marketing emails included in these prices?
Not always. Resend prices broadcasts by contacts. SendGrid Marketing Campaigns are a separate product. Postmark limits bulk streams by plan. SES can send both, billed per recipient.
Why is SendGrid’s included volume not listed?
The SendGrid pricing URL now routes to Twilio. The hub published the free daily cap and the $19.95 paid start. It did not publish included volume for that paid plan.
Is Amazon SES free for the first emails?
The pricing page we loaded did not state a monthly free email quota. À la carte outbound is $0.10 per 1,000.
Related comparisons
Last updated 6 October 2026. Pricing checked 6 October 2026.
Disclosure: Kurums is reader-supported. Some outbound links are marked sponsored and nofollow. They do not change order, labels or conclusions. This page has no Kurums Recommends, Top Pick or Verified badge.
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