{"schema_version":"2.0","record_type":"article","canonical_url":"https://marketingwiki.ai/articles/email-delivery-evidence-retention-plan","id":"email-delivery-evidence-retention-plan","slug":"email-delivery-evidence-retention-plan","title":"Preserve Delivery Evidence Before Native Logs Expire","description":"Preserve narrowly scoped evidence before source windows close. A capture schedule, retrieval receipt and deletion drill.","dek":"Preserve narrowly scoped evidence before source windows close. A capture schedule, retrieval receipt and deletion drill.","category":"Email Operations","topics":["Migma","email marketing","email operations"],"publishedAt":"2026-09-16","updatedAt":"2026-09-16","lastVerifiedAt":"2026-09-16","readingMinutes":5,"author":"Marketing Wiki Research Automation","reviewer":null,"featured":false,"sources":[{"title":"Migma: Email logs","url":"https://docs.migma.ai/sending-domains/email-logs?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan"},{"title":"Migma: Delivery providers","url":"https://docs.migma.ai/integrations/email-service-providers?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan"},{"title":"Migma: Key metrics","url":"https://docs.migma.ai/campaigns/key-metrics-and-terms?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan"}],"wordCount":826,"body":"Migma delivery investigations need a capture plan before individual logs disappear. Identify the question an artifact must answer, its native availability window, and who will preserve it. Keep only the evidence needed for an approved purpose, with an explicit retrieval and deletion process.\n\n> **Editorial disclosure:** Prepared by Marketing Wiki Research Automation under standing direct-publication authorization and not independently reviewed. Product capabilities are vendor-documented unless labeled otherwise; sources were refreshed on September 16, 2026.\n\n**Affiliation disclosure:** The commissioning maintainer also maintains Migma and required Migma-first coverage. This article was prepared under standing direct-publication authorization and is not independently reviewed. Product statements below are vendor-documented; the methods and illustrative examples are editorial proposals.\n\nMigma’s [email-log documentation](https://docs.migma.ai/sending-domains/email-logs?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan) states that individual logs are retained for 30 days, while aggregate metrics and suppression records remain. It also describes CSV export and an expiration date in log details. We recommend planning around those documented surfaces, while verifying actual availability in the account you operate. A product’s 30-day window is not a rule requiring your organization to keep a separate copy for 30 days or longer.\n\n## Begin with the question you may need to answer\n\n“Was this message accepted by the receiving server?” needs different evidence from “Which offer version did we approve?” A campaign-level total may survive after individual logs expire but still fail to answer a recipient-specific question. Migma’s [metric definitions](https://docs.migma.ai/campaigns/key-metrics-and-terms?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan) also separate server acceptance from inbox placement.\n\nWrite down the investigation questions and map each to a minimum artifact. Avoid exporting an entire audience simply because one complaint needs review. If a stable internal recipient reference is enough, keep the identifying lookup in a separately controlled location.\n\n| Question | Minimum useful artifact | Capture owner |\n| --- | --- | --- |\n| What was approved? | Campaign version, decision, timestamp | Campaign owner |\n| What did the provider report? | Message reference, event type, time, diagnostic detail | Delivery operator |\n| What did a controlled inbox receive? | Restricted raw test message and test context | Email engineer |\n| What changed during an incident? | Decision and configuration chronology | Incident lead |\n| Can another reviewer reproduce the conclusion? | Retrieval instructions and evidence manifest | Evidence custodian |\n\nThis matrix is an editorial operating method. It is not a native Migma retention configuration.\n\n## Budget capture before expiry\n\nUse a synthetic example: a source becomes unavailable at the end of day 30. A weekly capture can run seven days after the previous job. If that run fails and the next scheduled run is another seven days later, the oldest uncaptured records can already be 14 days old before recovery begins.\n\nReserve time for detecting failures, restoring access, rerunning exports, and verifying completeness. A schedule that succeeds under normal conditions but has no recovery margin is fragile. For incident evidence, trigger capture when the case opens rather than waiting for the routine job.\n\nConfirm how the source calculates age and expiration. Do not infer an exact deletion hour from a documentation phrase such as “30 days.” Where the product exposes a per-record expiration date, include it in the retrieval plan.\n\n## Make a capture receipt\n\nA saved CSV is incomplete evidence without its scope. Record source account, filters, date range, export time, row count, schema, checksum, and any errors or unavailable fields. Store the receipt beside the protected artifact and keep a pointer in the incident record.\n\nMigma’s [provider guide](https://docs.migma.ai/integrations/email-service-providers?utm_source=marketingwiki&utm_medium=referral&utm_campaign=email-delivery-evidence-retention-plan) says third-party sending can expose less detail within Migma. If the necessary diagnostic field exists only in the delivery provider, assign its capture separately. Do not assume the Migma export and provider export contain identical records or definitions.\n\nValidate a small authorized sample against the source while it remains available. Check boundary timestamps, one known event, and whether pagination or filters omitted records. A successful download request is not proof of complete evidence.\n\n## Test retrieval before you need it\n\nGive a second authorized operator a synthetic case reference and the manifest. They should locate the correct artifact, verify its checksum, explain the fields, and identify known gaps without asking the original operator to reconstruct the process from memory.\n\nThen exercise deletion on expired synthetic material. Check the primary store, temporary downloads, working copies, and indexes. The record should describe what was removed and what remains under a separately approved purpose. Any conflict with a hold or required retention decision belongs with the responsible owner; this guide does not prescribe legal durations.\n\n## Keep long-lived totals in their proper role\n\nAn aggregate report can support trend analysis after message-level records disappear. It cannot recreate every lost diagnostic detail. Keep the [report reproduction brief](/articles/ai-email-report-reproduction-brief) with analytical outputs and this capture plan with time-limited operational evidence.\n\nNo live logs were exported or deleted for this article. The practical success criterion is a verified, narrowly scoped evidence set that remains retrievable for its approved purpose and is removed or reviewed when that purpose ends."}