Freedom251 › Email Testing Software
MailTester
What MailTester is
MailTester checks why emails may land in spam and returns a deliverability score out of 10. To run a test, generate a disposable address, send an email to it and receive a report in seconds. The score begins at 10 and falls when issues are detected; the report explains penalties and suggests fixes. Checks include SPF, DKIM, DMARC, domain alignment, reverse DNS and forward-confirmed reverse DNS. It also checks sending IPs against Spamhaus, SpamCop, Barracuda and other DNS blocklists.
Content analysis covers HTML, text-to-image ratio, links, subject, List-Unsubscribe and Message-ID. Rspamd analyzes messages and reports a spam score with triggered rules. Newsletter checks include one-click List-Unsubscribe (RFC 8058), message size and text-to-image ratio. MailTester is available on the web, through an API and as self-hosted software. The API can create test addresses and return report status and scores as JSON. Its free plan requires no account and offers 25+ checks per test. The maker says testing systems run on its own infrastructure, messages are retained only as long as needed to display the report, and the .eu edition is configured for full GDPR compliance.
Who it suits
MailTester suits people checking email deliverability, monitoring multiple domains or seeking API access and a tailored plan. Its no-account free plan may suit users who want to run individual tests.
What it does well
- Reports a deliverability score and suggested fixes.
- Checks authentication records and sending-IP blocklists.
- Newsletter checks include one-click List-Unsubscribe.
- Free plan requires no account.
- API returns report status and scores as JSON.
What to know first
- No free trial is listed.
- Paid pricing is available on request.
Limits
The free plan provides 25+ checks per test and requires no account. Paid plan pricing is available on request.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | No account needed · 25+ checks per test | Free |
As mailtester.eu lists them, read 7 Oct 2026. The maker's own page has the final word.
Getting started
- Open https://www.mailtester.eu/.
- Generate a disposable test address.
- Send the email you want to check to that address.
- Review the report, score, penalties, and suggested fixes.
- For automated checks, use the API to create test addresses and read report status and scores as JSON.
Verdict
MailTester combines authentication, blacklist and content checks with a score and issue explanations. Its free plan provides 25+ checks per test without an account; pricing beyond that is on request.
Questions
Is MailTester free?
Yes. Its free plan costs nothing, requires no account, and provides 25+ checks per test.
Does MailTester offer a free trial?
No. The listed free option is a plan rather than a free trial.
What platforms are available?
MailTester lists web, API, and self-hosted platforms.
What does MailTester check?
It checks authentication, domain alignment, DNS, blocklists, message content, and spam signals. Newsletter checks also include one-click List-Unsubscribe, message size, and text-to-image ratio.
How does the API work?
The API can create test addresses and return report status and scores as JSON.
How long are messages retained?
The FAQ says messages are kept only as long as needed to show the report.
Facts from MailTester's own pages
- API
- The API can create test addresses and read report status and scores as JSON. · mailtester.eu, 7 Oct 2026
- Authentication checks
- It checks SPF, DKIM, DMARC, domain alignment, reverse DNS, and forward-confirmed reverse DNS. · mailtester.eu, 7 Oct 2026
- Blacklist checks
- It checks sending IPs against Spamhaus, SpamCop, Barracuda, and other DNS blocklists. · mailtester.eu, 7 Oct 2026
- Bulk email checks
- The service checks one-click List-Unsubscribe (RFC 8058), message size, and text/image ratio for newsletter testing. · mailtester.eu, 7 Oct 2026
- Content analysis
- It analyzes HTML, text/image ratio, links, subject, List-Unsubscribe, and Message-ID. · mailtester.eu, 7 Oct 2026
- Data retention
- The FAQ says messages are kept only as long as needed to show the report. · mailtester.eu, 7 Oct 2026
- Infrastructure
- The maker says the SMTP server, authentication checks, blacklist queries, and Rspamd engine run on its own infrastructure, with no data leaving its perimeter. · mailtester.eu, 7 Oct 2026
- Intended users
- The maker invites users to test deliverability, monitor multiple domains, or request API access and a tailored plan. · mailtester.eu, 7 Oct 2026
- Privacy
- The maker describes the .eu edition as configured for full GDPR compliance. · mailtester.eu, 7 Oct 2026
- Purpose
- MailTester checks why emails may land in spam and returns a deliverability score out of 10. · mailtester.eu, 7 Oct 2026
- Scoring
- The score starts at 10, subtracts points for detected issues, and explains penalties with suggested fixes. · mailtester.eu, 7 Oct 2026
- Spam analysis
- Messages are analyzed by Rspamd, with a spam score and a list of triggered rules. · mailtester.eu, 7 Oct 2026
- Support
- The contact page says inquiries receive a reply within one business day. · mailtester.eu, 7 Oct 2026
- Test workflow
- Generate a disposable address, send the email to it, and receive a report in seconds. · mailtester.eu, 7 Oct 2026
Where MailTester stands on Freedom251
- Email Testing Software#12 of 28