Email Sender Inventory Template
A sender inventory prevents legitimate systems being forgotten when SPF, DKIM or DMARC changes.
List workflows
Include ordinary mailboxes, websites, billing, support, marketing, recruitment, monitoring and devices. The vendor list is not enough when one service sends through several routes.
Record identities
For each route record the visible From domain, envelope domain, DKIM signing domain, selector and sending provider. Do not store credentials in the inventory.
Capture proof
Link a dated, redacted received-header test showing SPF, DKIM and DMARC outcomes. A configured administration screen does not prove the message path.
Name an owner
Assign a business owner and technical contact who can confirm whether the sender is still required. Unknown sources should be investigated, not automatically authorised.
Track changes
Record onboarding, key rotation, provider migration and retirement dates. Remove obsolete authorisation only after normal delivery and retry windows are understood.
Review before enforcement
Use aggregate DMARC evidence and the inventory together before increasing policy. Preserve the former DNS value, TTL and rollback decision.
Authoritative references
Read the underlying standards and provider instructions before changing production DNS: RFC 7208 (SPF), RFC 9989 (DMARC), Google Workspace SPF guidance and your sending provider's current DKIM documentation.
Download the sender inventory worksheet
Editorial responsibility
Published by Acerville Sparks Limited. Software assists research, drafting and automated record testing. Internet standards, provider documentation, reproducible checks and limitations are shown so readers can inspect the work. No independent deliverability consultant review is claimed. Reviewed 4 September 2026.
What this site does not do
No inbox guarantee. No live DNS checks. No storage of entered data. No passwords or private keys requested.