Mail-Tester vs Postmark

Mail-Tester checks an email, its mail server, and sending IP, then gives a spam score and reports configuration findings. To run a test, send a message to an address generated by the service and open the result page. Checks include blocklists, SpamAssassin, SPF, DKIM, Sender-ID, DMARC, links, and pictures. The free plan allows three tests within a rolling 24-hour period. A test counts after a new message is sent, the result page is requested, and the result is returned successfully; reopening that result does not use another test. Free results remain available for 7 days. With an account using its own prefix, results remain available for 30 days. Accounts also provide white-labeling, result-page CSS customization, statistics, a 30-day test listing, and pages without ads. Paid plans include an iframe and JSON API for integration; API output can include message details, authentication checks, body analysis, blacklist results, and broken links. One-time test bundles cost $5 as a one-time purchase to $250, paid once; monthly plans cost $10 a month to $250 a month. Passing does not guarantee inbox placement.

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.