Transactional email APIs · #10 of 16 · ↑ Mailjet · ↓ Elastic Email
Postal
Postal ranks #10 of 16 in transactional email apis in the week of 28 September 2026, with a visibility score of 7 across ChatGPT, Claude, Gemini and Perplexity. It was named in 8% of the answers we sampled.
sampled: 3 of 4 assistants this week
Postal shows up in just 5 of 62 answers across AI assistants, landing an overall score of 7 out of 100 (ChatGPT 5, Claude 11, Perplexity 5). Its one clear strength: when the question is specifically about open-source or self-hosted transactional email servers, Postal is named in all 3 of 3 answers. Outside that niche, mentions thin out fast, including a single nod each for high-volume-at-low-cost and cheapest-at-scale questions. It's never named for broader questions about webhooks, deliverability, general "best transactional email APIs" lists, Next.js or serverless setups, or developer-focused picks.
this is mine claim it, free, forever. We also check whether ChatGPT and Claude can read postalserver.io.
Who's talking about you
| assistant | score | named in, this week | usual spot, this week |
|---|---|---|---|
| ChatGPT | 5 | 5% of answers | #1.0 |
| Claude | 11 | 15% of answers | #3.7 |
| Gemini | not sampled this week | ||
| Perplexity | 5 | 5% of answers | #1.0 |
Questions you win
| question | named in | best spot |
|---|---|---|
| What's the best open-source or self-hosted transactional email server? | 3 of 3 | #1 |
| What's the cheapest way to send transactional email at scale? | 1 of 3 | #2 |
| What's the best transactional email provider for high volume at low cost? | 1 of 3 | #8 |
Questions you lose
| question | who got named instead |
|---|---|
| What are the best transactional email APIs? | Postmark, Amazon SES, Resend |
| What's the best email API for developers? | Resend, Postmark, Mailgun |
| What's the best alternative to SendGrid? | Postmark, Amazon SES, Resend |
| Which email API has the best deliverability? | Postmark, Amazon SES, Mailtrap |
| Which transactional email service is best for a startup? | Postmark, Resend, Amazon SES |
| What's the best email API in 2026? | Resend, Postmark, Amazon SES |
| Which email API has the best free tier? | Brevo, Resend, Mailjet |
| What's the best SMTP service for an app? | Postmark, Resend, Amazon SES |
| Which transactional email provider has the best developer experience? | Resend, Postmark, SendGrid |
| What's the best way to send password reset and verification emails from my app? | Postmark, Amazon SES, Resend |
| What's the best email API for a Next.js or serverless app? | Resend, Postmark, SendGrid |
| What's the best email API with React or JSX email templates? | Resend, Postmark |
| What's the best tool to test and preview emails before sending? | nobody in particular |
| What's the best email service for sending receipts and order confirmations? | Postmark, Resend, Amazon SES |
| What's the best email API with webhooks for bounces and opens? | Postmark, Resend, Mailgun |
| What's the best email API that also handles marketing campaigns? | SendGrid, Brevo |
| What's the best email API for a European company that needs EU data hosting? | Brevo, Mailgun, Mailjet |
Assistants cited 10 pages for questions in this category that name your rivals and not you. Claim to see them. See all sources for Transactional email APIs.
In their words
- ChatGPT“| Postal | Full self-hosted SendGrid/Mailgun replacement | ✅ | ✅ | Medium |”
- Claude“One option I'd steer away from: self-hosting Postal or Haraka.”
- Perplexity“Postal is the best general-purpose choice for a self-hosted transactional email server.”
Closest rivals
- Postal vs Elastic Email5
- Postal vs Mailjet9
- Postal vs Loops4
- Postal vs MailerSend10
- Postal vs Scaleway TEM3
All Postal alternatives · Full Transactional email APIs leaderboard · Sources