InboxGreen vs Mail-Tester

Which tool actually fixes your email deliverability problem?

Short answer: Mail-Tester checks a test email you send to a temporary address and gives it a spam score. InboxGreen checks your domain's DNS authentication records (SPF, DKIM, DMARC) directly - no test email required - and tells you exactly what to fix with copy-paste DNS records. They solve different parts of the problem. If you are unsure which one you need, start with InboxGreen's free domain check.

Mail-Tester

Spam score tester

Send a test email to a unique address. Get a spam score out of 10. Checks content, headers, blacklists, and authentication results from an actual sent email.

Free: 3 tests/day

Paid from ~$49/month (unlimited tests)

InboxGreen

Email authentication fix kit

Check SPF, DKIM, and DMARC directly in DNS without sending a test email. Get copy-paste fix records for Cloudflare, Namecheap, Google Workspace, and more.

Free check - no account needed

FixKit $29 one-time - Monitor from $19/mo

Feature comparison

Feature InboxGreen Mail-Tester
Check SPF / DKIM / DMARC Yes - direct DNS lookup, instant Yes - from a sent test email
Requires sending a test email No - checks DNS directly Yes - must send to a temp address
Copy-paste DNS fix records Yes - formatted per DNS provider No - shows what is wrong but not how to fix
Spam content scoring No Yes - SpamAssassin-based score
Check email content / subject line No Yes
Blacklist check Free - try it Yes (included in score)
SPF record generator Free - try it No
DMARC record generator Free - try it No
DKIM key generator Free - try it No
Ongoing DNS monitoring + alerts Yes - from $19/mo No ongoing monitoring
PDF report for clients Yes - Agency plan $99/mo No
No account required Yes Yes (for free tests)

When to use Mail-Tester

  • You want to test whether an actual email you are about to send will pass spam filters.
  • You want a spam score that factors in content, subject line, and HTML structure.
  • You are a developer or marketer debugging a transactional or marketing email campaign.
  • You want to see how your email renders across authentication checks from an actual SMTP delivery.

When to use InboxGreen

  • You want to check and fix SPF, DKIM, or DMARC without having to send a test email.
  • You need exact DNS records to copy and paste into Cloudflare, Namecheap, or GoDaddy.
  • You manage email for a business or clients and want ongoing monitoring when records break.
  • You are starting from scratch and need to generate SPF, DKIM, and DMARC records.
  • You need a PDF deliverability report to share with clients.

Pricing comparison

Mail-Tester offers 3 free tests per day on the free plan. Unlimited tests require a paid subscription starting around $49/month. There is no ongoing monitoring or alerting - it is a test-on-demand tool.

InboxGreen pricing:

  • Free: Full SPF/DKIM/DMARC domain check, blacklist check, 11 free tools - no account needed.
  • FixKit ($29 one-time): Copy-paste DNS records for your registrar + PDF guide. No subscription.
  • Monitoring ($19/month): Daily checks, email alerts when records change or fail, up to 5 domains.
  • Agency ($99/month): Up to 30 domains, white-label PDF reports for client deliverability audits.

For checking and fixing DNS authentication records, InboxGreen costs $29 one-time vs Mail-Tester's $49/month for unlimited tests.

Check your domain free - no account, no test email needed.
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Frequently asked questions

Is Mail-Tester accurate for checking email authentication?

Mail-Tester is accurate in that it shows real authentication results from an actual sent email. However, it requires you to send a test email each time. InboxGreen checks your DNS records directly, which means you do not need to send anything and can check any domain instantly.

Can Mail-Tester tell me how to fix SPF, DKIM, or DMARC?

Mail-Tester shows whether these checks passed or failed, but it does not generate the fix records you need to publish. InboxGreen's FixKit generates the exact TXT records formatted for your specific DNS provider.

Does InboxGreen test spam score like Mail-Tester does?

No. InboxGreen focuses on DNS authentication (SPF, DKIM, DMARC) rather than content scoring. If you need to check whether your email content triggers spam filters, Mail-Tester is the right tool for that. For most deliverability problems caused by authentication failures, InboxGreen is the faster fix.

What is the best free Mail-Tester alternative?

InboxGreen is the best alternative for checking and fixing DNS authentication records - it is free, requires no account, and covers SPF, DKIM, and DMARC in one check. For content-based spam testing, Mail-Tester's free tier (3 tests/day) remains a solid option alongside InboxGreen.

My Mail-Tester score is 10/10 but emails still go to spam - why?

A 10/10 score on Mail-Tester means your test email passed its checks, but deliverability problems can still exist due to sender reputation, IP warming, engagement rates, or list quality. Run a full DNS check with InboxGreen to confirm authentication is solid, then consider whether the problem is reputation-based rather than configuration-based.