Asked of ChatGPT, Gemini and Claude

“cheapest transactional email API”

Which products each AI assistant recommends for this question, in the order it names them.

What each AI said

ChatGPT

November 7, 2026 · gpt-5-mini-2025-08-07

Amazon SES
Elastic Email
Mailgun
SparkPost
Brevo
Postmark

Claude

November 7, 2026 · claude-haiku-5-5

Amazon SES
Brevo
SMTP2GO
Mailtrap
Postmark
Resend
SendGrid

Gemini

November 7, 2026 · gemini-2.5-flash

Amazon SES
SendGrid
Mailgun
SparkPost

The full answers

Exactly what each AI said, with the products we counted marked.

ChatGPT's answer

Short answer: Amazon SES is usually the cheapest reliable transactional-email API. Elastic Email and some pay-as-you-go tiers from Mailgun / SparkPost can also be very low cost. Price alone isn’t the only factor — deliverability, support, quotas and ease of integration matter.

Quick provider summary (approximate/practical points as of mid‑2024):

Amazon SES
Price: ~ $0.10 per 1,000 emails sent (plus small data/attachment charges). If sending from an EC2 instance there’s a free 62k/mo allowance.
Pros: Very low cost, global infra, good deliverability, mature API/SMTP, scale.
Cons: Slightly more setup and AWS knowledge required for best practices (IAM, DKIM, bounce handling).
Elastic Email
Price: Among the lowest advertised; pay-as-you-go and low monthly plans. (Check current site for exact tiers.)
Pros: Cheap, simple dashboard and SMTP/API.
Cons: Mixed reputation in the past on deliverability; review recent deliverability reports and limits.
Mailgun
Price: Pay-as-you-go / tiered. Low-cost options exist but more expensive than SES at scale.
Pros: Good API, features for logs/analytics, deliverability tools.
Cons: Cost increases with features; strict verification for high volumes.
SparkPost
Price: Free tier available; paid tiers for higher volume. Cost competitive but usually higher than SES for raw volume.
Pros: Good analytics and deliverability tooling.
Cons: Pricing/limits vary by plan.
Brevo (formerly Sendinblue)
Price: Free tier (limited daily sends), paid plans are affordable but measured differently (daily/monthly caps).
Pros: GDPR-friendly, good for EU customers, built-in marketing features.
Cons: Not the absolute cheapest per-email at very high volumes.
Postmark
Price: More expensive than the above.
Pros: Best-in-class for transactional deliverability, great developer UX and support.

How to pick (short checklist):

If absolute lowest cost per email and you can handle AWS: Amazon SES.
If you want an easy UI + good features and don’t need rock-bottom price: Mailgun or SparkPost.
If deliverability and support are critical and cost is secondary: Postmark.
If you need EU data residency/GDPR options: Brevo may be preferable.
Check free tier/trial to test deliverability to your recipients before committing.

If you want, tell me:

your expected monthly volume,
whether you need dedicated IPs,
where your users are located (region/residency concerns),
language/framework you’ll integrate with,

and I’ll recommend the best provider and a short setup checklist (e.g., DNS records, bounce handling, testing).

Claude's answer

Here are the most cost-effective transactional email APIs, roughly from cheapest to pricier at scale (pricing changes often, so verify before committing):

Free / very low cost

Amazon SES: About $0.10 per 1,000 emails, plus data transfer fees. Cheapest at high volume, but requires more setup (domain verification, sandbox exit request) and has a steeper learning curve.
Brevo (formerly Sendinblue): Free tier of about 300 emails/day, then paid plans starting around $9/month for 5,000+ emails. Good if you also want marketing email.
SMTP2GO: Free tier of around 1,000 emails/month, paid plans from about $10/month.
Mailtrap: Free tier for small projects, with paid plans from about $15/month. Developer-focused.

Mid-range, developer-friendly

Postmark: Around $15/month for 10,000 emails. Excellent deliverability for transactional mail and a clean API, but no bulk marketing.
Resend: Free tier of 3,000 emails/month, then about $20/month for 50,000. Very modern developer experience.

Gemini's answer

When looking for the "cheapest" transactional email API, you need to consider a few factors beyond just the per-email cost:

Free Tiers: How generous are they and are they ongoing or time-limited?
Per-Email Cost at Scale: What happens when you send thousands or millions of emails?
Ease of Use/Setup: Is your time valuable? A cheaper service that takes days to configure might not be truly cheaper.
Deliverability: A cheap email that goes to spam is worthless.

Here's a breakdown of the top contenders for "cheapest," along with their pros and cons:

---

1. Amazon SES (Simple Email Service)

Cheapest Per-Email Cost: Generally the absolute cheapest per email, especially at higher volumes.
Free Tier:
62,000 emails/month free if you send them from an application hosted on Amazon EC2 (or AWS Lambda).
1,000 emails/month free if you send from outside EC2.
Paid Pricing: After the free tier, it's typically $0.10 per 1,000 emails.
Pros:

Named most for this question

1
Amazon SES100% of answers
Named in 3 of 3Average place #1ChatGPTClaudeGemini
2
Mailgun67% of answers
Named in 2 of 3Average place #3ChatGPTGemini
3
Brevo67% of answers

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The full answers

Exactly what each AI said, with the products we counted marked.

ChatGPT's answer

Quick provider summary (approximate/practical points as of mid‑2024):

Amazon SES
Price: ~ $0.10 per 1,000 emails sent (plus small data/attachment charges). If sending from an EC2 instance there’s a free 62k/mo allowance.
Pros: Very low cost, global infra, good deliverability, mature API/SMTP, scale.
Cons: Slightly more setup and AWS knowledge required for best practices (IAM, DKIM, bounce handling).
Elastic Email
Price: Among the lowest advertised; pay-as-you-go and low monthly plans. (Check current site for exact tiers.)
Pros: Cheap, simple dashboard and SMTP/API.
Cons: Mixed reputation in the past on deliverability; review recent deliverability reports and limits.
Mailgun
Price: Pay-as-you-go / tiered. Low-cost options exist but more expensive than SES at scale.
Pros: Good API, features for logs/analytics, deliverability tools.
Cons: Cost increases with features; strict verification for high volumes.
SparkPost
Price: Free tier available; paid tiers for higher volume. Cost competitive but usually higher than SES for raw volume.
Pros: Good analytics and deliverability tooling.
Cons: Pricing/limits vary by plan.
Brevo (formerly Sendinblue)
Price: Free tier (limited daily sends), paid plans are affordable but measured differently (daily/monthly caps).
Pros: GDPR-friendly, good for EU customers, built-in marketing features.
Cons: Not the absolute cheapest per-email at very high volumes.
Postmark
Price: More expensive than the above.
Pros: Best-in-class for transactional deliverability, great developer UX and support.

How to pick (short checklist):

If absolute lowest cost per email and you can handle AWS: Amazon SES.
If you want an easy UI + good features and don’t need rock-bottom price: Mailgun or SparkPost.
If deliverability and support are critical and cost is secondary: Postmark.
If you need EU data residency/GDPR options: Brevo may be preferable.
Check free tier/trial to test deliverability to your recipients before committing.

If you want, tell me:

your expected monthly volume,
whether you need dedicated IPs,
where your users are located (region/residency concerns),
language/framework you’ll integrate with,

and I’ll recommend the best provider and a short setup checklist (e.g., DNS records, bounce handling, testing).

Claude's answer

Here are the most cost-effective transactional email APIs, roughly from cheapest to pricier at scale (pricing changes often, so verify before committing):

Free / very low cost

Amazon SES: About $0.10 per 1,000 emails, plus data transfer fees. Cheapest at high volume, but requires more setup (domain verification, sandbox exit request) and has a steeper learning curve.
Brevo (formerly Sendinblue): Free tier of about 300 emails/day, then paid plans starting around $9/month for 5,000+ emails. Good if you also want marketing email.
SMTP2GO: Free tier of around 1,000 emails/month, paid plans from about $10/month.
Mailtrap: Free tier for small projects, with paid plans from about $15/month. Developer-focused.

Mid-range, developer-friendly

Postmark: Around $15/month for 10,000 emails. Excellent deliverability for transactional mail and a clean API, but no bulk marketing.
Resend: Free tier of 3,000 emails/month, then about $20/month for 50,000. Very modern developer experience.

Gemini's answer

When looking for the "cheapest" transactional email API, you need to consider a few factors beyond just the per-email cost:

Free Tiers: How generous are they and are they ongoing or time-limited?
Per-Email Cost at Scale: What happens when you send thousands or millions of emails?
Ease of Use/Setup: Is your time valuable? A cheaper service that takes days to configure might not be truly cheaper.
Deliverability: A cheap email that goes to spam is worthless.

Here's a breakdown of the top contenders for "cheapest," along with their pros and cons:

---

1. Amazon SES (Simple Email Service)

Cheapest Per-Email Cost: Generally the absolute cheapest per email, especially at higher volumes.
Free Tier:
62,000 emails/month free if you send them from an application hosted on Amazon EC2 (or AWS Lambda).
1,000 emails/month free if you send from outside EC2.
Paid Pricing: After the free tier, it's typically $0.10 per 1,000 emails.
Pros:

What each AI said

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