Mail-Tester
Send-a-message spam and authentication scoring for pre-send QA.
- Reading time:
- 5 min
- Difficulty:
- Intermediate
- Estimated duration:
- 5 min
- Prerequisites:
- None
- Last updated:
- 2026-07-15
- Author:
- empire
Overview
Send-a-message spam and authentication scoring for pre-send QA.
Vendor: Mail-Tester
Primary purpose
Score a real outbound message for spam signals and authentication results.
Best for
- Pre-send QA of templates and auth alignment
Common use cases
- Confirm SPF/DKIM/DMARC on a sample send
- Catch obvious spam-filter triggers before a campaign
Advantages
- Simple workflow
- Combines auth and content signals
Limitations
- Single vantage point — not full inbox placement
- Scores are directional, not provider guarantees
When not to use it
- You need multi-provider inbox placement sampling at scale
- You are testing with highly sensitive message content
Pricing
Limited free tests; paid for higher volume.
Official website
Inputs and outputs
Typical inputs
- Outbound test message to a provided address
Typical outputs
- Score
- Auth results
- Content findings
Privacy notes
- Do not send confidential or regulated content to third-party test inboxes.
Related Learn Articles
Related Solve Articles
- Broken DKIM key rotationKey rotation leaves selectors unpublished or mismatched.
- DKIM body hash mismatchBody modifications invalidate the DKIM body hash.
- DKIM key too shortDKIM key length is below accepted operational guidance.
- DKIM passes but DMARC failsDKIM validates but signing domain does not align for DMARC.
- DKIM public key invalidPublished DKIM key material cannot be used for verification.
- DKIM selector not foundThe selector DNS record cannot be located.
- DKIM signature missingMessages leave without a verifiable DKIM signature.
- DKIM signing-domain mismatchUnexpected d= domain relative to the visible From domain.
- DKIM verification failureReceivers cannot validate the DKIM signature.
- Broken SPF includeAn included SPF domain is missing, invalid, or fails closed.
- Forwarded email fails SPFForwarding paths break SPF because the forwarder is not authorized.
- Incorrect IP authorizationSending infrastructure IPs are not authorized by SPF.
- Invalid SPF mechanismSPF record contains unsupported or malformed mechanisms.
- Multiple SPF recordsMore than one SPF TXT record exists, causing evaluation failure.
- SPF passes but DMARC failsSPF authenticates a domain that does not align for DMARC.
- SPF PermErrorSPF evaluation fails permanently due to policy or lookup errors.
- SPF record missingNo SPF TXT record is published for the sending domain.
- SPF TempErrorTemporary DNS or evaluation failure during SPF checks.
- Too many DNS lookupsSPF evaluation exceeds the ten-lookup limit.
Alternatives & related tools
- GlockAppsInbox placement and deliverability testing across major mailbox providers.
- DKIMCoreDKIM key and signature oriented validation utilities.
- digCLI DNS lookup utility for authoritative and recursive inspection of mail-related records.
- MXToolboxPopular DNS and mail diagnostics suite for SPF, DMARC, blacklist, and MX checks.
- Kitterman SPF validatorClassic web SPF policy evaluator used by operators for syntax checks.
Related Workflows
- Authenticate a new domainPublish SPF, DKIM, and DMARC for a new sending domain and verify authentication before warmup.
- Configure DKIMEnable DKIM signing and publish selectors.
- Migrate authentication recordsMove SPF, DKIM, and DMARC to a new platform without dual-record failures.
- Configure SPFPublish and validate an SPF policy for authorized senders.
- Audit multi-domain authenticationReview authentication across a domain portfolio.
- Check authenticationRegularly verify SPF, DKIM, and DMARC alignment and report pipelines.