Postmark vs Unspam.email
Postmark
postmarkapp.com
Unspam.email
unspam.emailSide by side
| Figure | Postmark | Unspam.email |
|---|---|---|
| Price from | $5/mo | $5/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Plans published | 8 | 7 |
| Spec score · Email Deliverability Software | 8.7 (#6) | 8.5 (#7) |
| Integrations | Official integrations include Slack, Zapier, Stripe, WordPress, Supabase, Bubble, Craft CMS, Netlify, and Gravity Forms. | The API is designed to receive real messages from SES, Postmark, SendGrid, Mailgun or a customer’s SMTP system. |
| Security | Postmark supports TLS and HTTPS, DKIM, SPF, DMARC, two-factor authentication, API permission controls, penetration testing, and DDoS protection. | The privacy policy says stored data is kept on services and providers certified to ISO/IEC 27001:2013, PCI DSS, SOC 1 Type II, and SOC 2 Type II or higher. |
| Support | Postmark offers support by email, live chat, and one-on-one calls and reports a 95% customer happiness rating. | The company lists support chat and [email protected] for support or product inquiries. |
| What it does | Postmark delivers and tracks application email as a replacement for SMTP or Sendmail. | Unspam.email is a deliverability platform combining spam tests, authentication and blacklist checks, previews, heatmaps and inbox-placement testing. |
Plans
Postmark
- FreeFree
- Basic$15 a month
- Pro$16.50 a month
- Platform$18 a month
- Custom activity retention$5 a month
- DMARC monitoring$14 a month
- Dedicated IP$50 a month
- High-volume plansPriced on request
Unspam.email
- FreeFree
- No accountFree
- Custom plan$5 a month
- Basic$9 a month
- Business$19 a month
- Agency$29 a month
- White LabelPriced on request
In their own words
Postmark
Postmark delivers and tracks application email as an alternative to SMTP or Sendmail. It separates transactional and broadcast messages into different Message Streams and IP infrastructure. Developers can send through REST API, SMTP, or multi-region SMTP routing, with official libraries for Node.js, Python, Rails, Ruby, PHP, and.NET. Inbound messages can be converted to JSON and sent to a webhook URL. Tracking includes delivery, bounces, spam, opens, and links, with event webhooks. Editable responsive templates cover transactional messages such as password resets, receipts, and invitations. The free Developer plan costs nothing, provides 100 emails per month, permits no overages, and does not expire. Basic starts at $15 a month for 10,000 emails per month; extra emails cost $1.80 per 1,000 and are calculated at the end of the billing cycle. Unused emails do not roll over. Postmark lists API and web access. Its iOS app was sunset in June 2025 and is no longer supported.
Unspam.email
Unspam.email is an email deliverability platform for examining spam signals, sender authentication, blacklists, previews, and inbox placement. Spam tests assess authentication, sender reputation, blacklists, and message content, then show which checks affected the score. Inbox placement tests send a campaign to seed mailboxes at Gmail, Outlook, Yahoo, and other providers and report where it landed. Email previews cover rendering across more than 50 real clients and devices in light and dark modes. Scheduled tests can track placement and spam scores and send alerts by email when results decline. Its API has 39 endpoints across seven areas and can test mail sent through SES, Postmark, SendGrid, Mailgun, or a sender’s own SMTP setup; an MCP server lets compatible AI clients run tests and retrieve results. The free plan includes 21 tests per month, unlimited sender accounts, and 14-day data retention, but excludes DMARC monitoring and full API access. Custom costs $5 a month, with a $5 monthly minimum and pay-per-test rates.