AuthEmailTest.comEmail Delivery Diagnostics
About AuthEmailTest.com
AuthEmailTest.com tests what actually happens when your mail system sends a message to this receiving server. DNS-only checks are useful, but they cannot show the real connecting IP, HELO name, envelope sender, header From address, DKIM signature domains, DMARC alignment, or spam filter scoring seen during SMTP delivery.
SPF
SPF checks whether the connecting SMTP server is authorised to send for the envelope sender domain. This live test records the IP and HELO used for the message and evaluates SPF from the receiver side.
DKIM
DKIM uses a cryptographic signature in the message and a public key in DNS. This test evaluates every DKIM-Signature separately, showing its selector, signing domain, verification result, key strength, alignment, signed-header and body-length details, signature timing, and whether it contributed to DMARC.
DMARC
DMARC checks whether SPF or DKIM passes in alignment with the visible From domain. Policy discovery and relaxed alignment follow the bounded DNS tree walk in RFC 9989. This is often where apparently separate SPF and DKIM details meet, especially when a provider sends with a different envelope sender or signing domain.
SMTP Session
The service records the connecting IP and HELO identity, checks PTR and forward-confirmed reverse DNS, checks whether HELO resolves to the connecting IP, and reports whether the sender used STARTTLS and which TLS version and cipher were negotiated.
Message Format
The service checks the raw RFC 5322 structure and core headers, message date, Message-ID, MIME boundaries and encodings, declared character sets, body alternatives, attachment metadata, SMTPUTF8 and 8BITMIME use, and RFC 8058 one-click unsubscribe headers when present.
ARC
When ARC headers are present, the service verifies the chain and reports whether its message signatures and seals validate. ARC can explain authentication preserved across forwarding, but it does not replace the receiver-side SPF, DKIM, or DMARC results.
Spam Filtering
After the message is accepted, AuthEmailTest.com runs Rspamd and SpamAssassin scans and reports their scores, actions, and main rules. These checks are useful diagnostics, but filtering decisions vary between providers and gateways.
Best-Practice Review
The report also highlights contextual message-level observations such as reply handling, subject style, email-safe HTML, image alternatives, link consistency, bulk-mail unsubscribe signals, attachment compatibility, and unusually large content. These suggestions are advisory and do not change the technical authentication, formatting, or spam-filter results.
One-Time Tests
You enter the address you intend to send from, complete verification, and receive a temporary address under incoming.authemailtest.com. It remains valid for 15 minutes or until one valid message is accepted. After the message arrives, the result page shows the SMTP session, sender identities, message formatting, authentication outcome, best-practice observations, and spam-filter results.
Account Tests
Verified accounts can keep a saved test history and use credit-limited reusable inbound addresses. Account reports are created only when a message is accepted, remain available only to the owning account, and use the same receiver-side authentication, formatting, best-practice, and spam-filter checks as one-time tests.
Reputation and Inbox Placement
A single receiver-side test cannot see mailbox providers' private reputation, complaint, bounce, engagement or final inbox-placement data. Read the deliverability guidance for those limits and the provider tools you can use.
Questions or Issues
If something looks wrong, or you want to share an authentication issue, please contact us.