Compare KingSMTP and Postmark side by side to see which transactional SMTP email service is the better fit for your business.
| Feature / Aspect | KingSMTP | Postmark |
|---|---|---|
| Primary Purpose | Transactional email delivery | Transactional email delivery |
| Delivery Method | SMTP + REST API | SMTP + REST API |
| Speed & Reliability | Fast and reliable | Fast and reliable |
| Privacy & Data Control | High — no unnecessary tracking; enhanced user privacy | Standard — GDPR-compliant, tracking optional |
| Payment Options | Bitcoin, Ethereum, USDT, Monero, any other Crypto | Traditional payments only |
| Pricing | Subscription-based | Subscription-based |
| Analytics & Reporting | Delivery logs, status tracking | Advanced dashboards & analytics |
| Compliance & Certifications | Privacy-focused | SOC 2, GDPR, HIPAA |
| Support | Email, Telegram | Email, knowledge base |
| Emails per month | KingSMTP | Postmark |
|---|---|---|
| 5,000 emails | $49 /year | Not available |
| 10,000 emails | $79 /year | $180 /year |
| 20,000 emails | $159 /year or $19 /mo | Not available |
| 50,000 emails | $490 /year or $49 /mo | $60.50 /mo |
| 100,000 emails | $890 /year or $99 /mo | Not available |
| 125,000 emails | $1240 /year or $124 /mo | $1380 /year or $115 /mo |
Why Look for a Postmark Alternative?
When it comes to transactional email, Postmark has built a reputation for speed and reliability. But not every business fits into the same box. Many startups, small businesses, and privacy-conscious teams are looking for an alternative that delivers the same focus on transactional email without the high costs or the rigid payment models of traditional providers.
That’s where KingSMTP comes in.
Founded in 2017 and built on open-source technology, KingSMTP was designed from the ground up for businesses that value privacy, affordability, and flexibility. Unlike Postmark, KingSMTP embraces cryptocurrency payments alongside traditional billing, giving global businesses — especially those underserved by mainstream payment systems — a straightforward way to send critical emails.
With KingSMTP, you still get what matters most:
- Fast and reliable email delivery for password resets, notifications, invoices, and more.
- A simple subscription model, paid annually, without complex overage fees.
- Privacy-first design, ensuring your email data isn’t over-collected or over-tracked.
- Personalized support, where you can actually talk to a real person if you need help.
If you love the transactional focus of Postmark but want an option that’s more affordable, crypto-friendly, and privacy-minded, KingSMTP is a strong alternative.
FAQ
Send us an email to upgrade your account.
KingSMTP is an email delivery and deliverability service that empowers businesses to easily send email from their (web) apps. It’s free to sign up and easy to get started.
Since KingSMTP has both an HTTP API and an SMTP endpoint, you can choose to send the way you’d like. Both ways have their advantages… SMTP is easy to setup and often plug and play, but API is much more reliable at scale. If you’re building an application, we recommend using our HTTP API.
You don’t actually need a dedicated IP when using KingSMTP, because great email delivery is already included in your plan, no additional investment is needed for this from your end.
Every KingSMTP plan (free and paid) allows you to add as many users as you need to your account at no additional cost. We think it’s much easier this way to manage the account with your team, without sharing login credentials.
The free trial is ideal for those looking to test out the service. Keep in mind that the free trial has a max 20 emails per hour limit and a max 20 recipients limit. If you reach these limits, your email traffic will be paused. The free plan has 30 days of log retention so you can easily troubleshoot issues. By default it has 0 recipients.