An email deliverability audit is a repeatable review of the technical, operational, and reputation signals that affect whether legitimate business mail reaches recipients. Use this template when launching a new sender, investigating spam placement, preparing a campaign, or running a quarterly domain-health review. The goal is a documented decision record, not a one-time score.
Audit scope and ownership
Record the domain, date, reviewer, business owner, DNS owner, and each sending platform in scope. Separate employee mail, transactional messages, support replies, and promotional campaigns. These streams often use different providers and can have different problems. Write down the audiences, approximate volume, and the person who can approve a configuration change.
Sender inventory
List every system that sends as the domain: mailbox provider, website forms, CRM, email marketing platform, billing tool, helpdesk, scheduling software, and agency service. For each one, record the visible From domain, return-path where known, DKIM selector, owner, purpose, and last test date. Flag unknown, unused, or retired services for investigation rather than leaving them authorized indefinitely.
SPF review
Capture the live SPF TXT value and confirm there is exactly one SPF record. Compare its mechanisms with the inventory. Check the expanded DNS lookup count, especially after adding CRM or marketing vendors. Send a fresh test from each important source and inspect headers for SPF results. Use SPF record examples and the lookup-limit guide for the technical checks.
DKIM review
For every relevant sender, inspect a fresh message for DKIM pass, signing domain, and selector. Confirm the public selector record resolves and is owned by the correct provider. Note a provider that signs only with its own unrelated domain, because it may not provide DMARC alignment for your visible From address. Record missing signing as a specific remediation item.
DMARC review
Capture the record at _dmarc, policy, percentage, reporting destinations, and any subdomain policy. Check whether fresh messages pass DMARC through aligned SPF or DKIM. Review aggregate reports if available, identifying legitimate sources, unknown sources, and failures. Do not confuse a published p=none record with enforcement. See the DMARC implementation checklist.
Reputation and list-quality review
Review complaints, hard bounces, unsubscribe behavior, volume changes, engagement, and list source by sending stream. Ask whether recipients expected the mail and whether the sender honors suppression lists. Technical authentication cannot offset high complaints or an unconsented audience. Keep transactional and marketing mail separate so their signals are not mixed.
Message and recipient tests
Send fresh test messages from each platform to a mailbox where full headers are available. Verify visible From identity, SPF, DKIM, DMARC, links, unsubscribe behavior where applicable, and whether the message arrives as expected. Test after DNS changes or a provider migration; old test messages do not prove the current configuration.
Findings and remediation
For each issue, record severity, confirmed evidence, owner, due date, and validation step. Treat a missing critical sender, duplicate SPF record, failed alignment, suspicious forwarding rule, or unexpected complaint spike as high priority. Make one change at a time where possible, keep the old value, and retest with fresh mail.
Ongoing review
Repeat this audit quarterly and after a rebrand, new vendor, domain migration, or major campaign change. Store the results with the sender inventory so the next reviewer begins from evidence rather than assumptions. Run Beacon’s free domain check to capture the public SPF, DKIM, and DMARC baseline for the audit record.