DOC 004 · DISCUSSIONS · 20 SCENARIOS
Deliverability & API discussions
Twenty original scenarios from production email work — each a self-contained 450+ word doc with symptom, cause, fix, and prevention. Editorial, no votes, no reviewer names.
Shared vs dedicated IP warmup: when to isolate reputation
Volume thresholds, warmup schedules, and the idle-IP trap.
Read D-01 →SPF, DKIM, DMARC setup checklist that actually passes
Alignment, subdomain policy, and monitoring before enforcement.
Read D-02 →Gmail spam false positives from API sends
Content, engagement, and authentication triage for Gmail placement.
Read D-03 →Bounce classification via webhooks: hard, soft, block
Mapping vendor events to suppression and retry policy.
Read D-04 →Complaint feedback loops and list hygiene
Keeping complaint rates under thresholds with fast suppression.
Read D-05 →Splitting transactional and marketing reputation
Subdomains, streams, and suppression boundaries.
Read D-06 →API rate limits and 429 retry strategy
Backoff, jitter, queues, and per-key budgeting.
Read D-07 →Suppression list sync across vendors
Unsubscribes, bounces, and complaints as portable truth.
Read D-08 →Double opt-in over API without killing signup
Token design, expiry, and deliverability payoff.
Read D-09 →Attachment size, encoding, and API delays
Why large payloads defer and how to link instead.
Read D-11 →HTML vs plain-text rendering and spam filters
Multipart discipline and client-proof templates.
Read D-12 →List-Unsubscribe headers and one-click RFC compliance
Gmail/Yahoo sender requirements made operational.
Read D-13 →Seed testing and inbox placement reads
Interpreting seed results without overreacting.
Read D-14 →High-volume bursts without reputation damage
Queue design, throttling, and stream isolation.
Read D-17 →Invalid-email validation before you send
Syntax, mailbox, trap, and role-address policy.
Read D-18 →Deliverability dashboard: metrics that matter
Bounce, complaint, deferral, and engagement signals.
Read D-20 →