Mail response notes

Mail SPF DKIM DMARC authentication failure

A practical cause and fix order for SPF/DKIM errors while operating Mail.

mediumMail5 min read

Mail SPF first triage response

A Mail first triage note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM first triage response

A Mail first triage note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC first triage response

A Mail first triage note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 first triage response

A Mail first triage note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 first triage response

A Mail first triage note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce first triage response

A Mail first triage note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist first triage response

A Mail first triage note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX first triage response

A Mail first triage note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth first triage response

A Mail first triage note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS first triage response

A Mail first triage note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF post-release regression response

A Mail post-release regression note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM post-release regression response

A Mail post-release regression note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC post-release regression response

A Mail post-release regression note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 post-release regression response

A Mail post-release regression note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 post-release regression response

A Mail post-release regression note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce post-release regression response

A Mail post-release regression note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist post-release regression response

A Mail post-release regression note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX post-release regression response

A Mail post-release regression note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth post-release regression response

A Mail post-release regression note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS post-release regression response

A Mail post-release regression note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF affected user or permission response

A Mail affected user or permission note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM affected user or permission response

A Mail affected user or permission note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC affected user or permission response

A Mail affected user or permission note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 affected user or permission response

A Mail affected user or permission note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 affected user or permission response

A Mail affected user or permission note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce affected user or permission response

A Mail affected user or permission note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist affected user or permission response

A Mail affected user or permission note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX affected user or permission response

A Mail affected user or permission note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth affected user or permission response

A Mail affected user or permission note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS affected user or permission response

A Mail affected user or permission note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF specific path failure response

A Mail specific path failure note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM specific path failure response

A Mail specific path failure note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC specific path failure response

A Mail specific path failure note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 specific path failure response

A Mail specific path failure note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 specific path failure response

A Mail specific path failure note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce specific path failure response

A Mail specific path failure note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist specific path failure response

A Mail specific path failure note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX specific path failure response

A Mail specific path failure note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth specific path failure response

A Mail specific path failure note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS specific path failure response

A Mail specific path failure note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF proxy versus origin split response

A Mail proxy versus origin split note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM proxy versus origin split response

A Mail proxy versus origin split note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC proxy versus origin split response

A Mail proxy versus origin split note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 proxy versus origin split response

A Mail proxy versus origin split note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 proxy versus origin split response

A Mail proxy versus origin split note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce proxy versus origin split response

A Mail proxy versus origin split note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist proxy versus origin split response

A Mail proxy versus origin split note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX proxy versus origin split response

A Mail proxy versus origin split note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth proxy versus origin split response

A Mail proxy versus origin split note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS proxy versus origin split response

A Mail proxy versus origin split note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF timeout and load response

A Mail timeout and load note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DKIM timeout and load response

A Mail timeout and load note for DKIM: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail DMARC timeout and load response

A Mail timeout and load note for DMARC: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 550 timeout and load response

A Mail timeout and load note for 550: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail 554 timeout and load response

A Mail timeout and load note for 554: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail bounce timeout and load response

A Mail timeout and load note for bounce: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail blacklist timeout and load response

A Mail timeout and load note for blacklist: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail MX timeout and load response

A Mail timeout and load note for MX: DNS resolution failure caused by missing records, wrong authority, stale TTL, policy records, or service target mismatch. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SMTP auth timeout and load response

A Mail timeout and load note for SMTP auth: authentication failure caused by expired token, redirect mismatch, cookie policy, CSRF state, or SMTP credential state. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail TLS timeout and load response

A Mail timeout and load note for TLS: SMTP TLS failure caused by STARTTLS negotiation, certificate mismatch, old cipher policy, port confusion, or mail relay trust settings. It includes evidence, output examples, branches, and the smallest reliable fix.

Mail SPF cache or propagation drift response

A Mail cache or propagation drift note for SPF: mail delivery failure caused by SPF/DKIM/DMARC alignment, MX routing, SMTP authentication, bounce policy, or blacklist reputation. It includes evidence, output examples, branches, and the smallest reliable fix.