Deliverability Incidents
Field-tested runbooks for the moments email breaks — inbox placement, authentication, reputation, bounces and more. Each incident opens with a first-15-minutes response and owner-specific fixes.
- Spam and Inbox Placement IncidentsDiagnose why legitimate mail suddenly lands in spam, junk or the Promotions tab across Gmail, Yahoo, Outlook and iCloud, and what a sender can change to recover placement.9 questions
- Authentication and DNS FailuresTrace SPF, DKIM, DMARC and reverse-DNS (PTR) failures — including DMARC that fails even when SPF or DKIM appears to pass — and decide which check to fix first.5 questions
- Reputation, Blocklists and Warm-upRecover from blocklist listings and damaged sender reputation, and plan safe warm-up for a new domain or IP when deliverability drops.5 questions
- Bounces, Rejections and ThrottlingRead SMTP response codes and separate permanent rejections from temporary deferrals and throttling across Gmail, Microsoft and ESPs, including sudden bounce-rate spikes after a platform switch.12 questions
- Complaints, Unsubscribe and Compliance IncidentsFix broken unsubscribe flows, one-click List-Unsubscribe and bulk-sender rules, investigate a rising complaint rate, and prove recipient consent during a compliance incident.11 questions
- Transactional Email OutagesRestore failing transactional mail — password resets, OTP and verification codes, and order confirmations that arrive late, duplicated or not at all — and make it reliable in a SaaS.10 questions
- Infrastructure, ESP and Migration IncidentsPlan an ESP migration without losing deliverability and resolve shared- and dedicated-IP reputation problems, including engagement drops that follow a move to new sending infrastructure.8 questions
- List Quality and Suppression FailuresContain a subscription-bombing attack, handle hard bounces from a reactivated or aging list, and close suppression gaps that skip intended recipients or push bounce rates up.6 questions
- Monitoring and Postmaster SignalsSet up and read Google Postmaster Tools, DMARC aggregate reports and ESP alerts, and investigate a deliverability incident even when monitoring gives no usable visibility.10 questions
- Security, Spoofing and Account CompromiseTell spoofing apart from account compromise, contain a hijacked sending account or leaked API key, and stop domain spoofing that continues even with SPF, DKIM and DMARC in place.8 questions
- Queues, Webhooks and Sending ReliabilityClear a stuck sending queue, make webhook processing idempotent when events arrive more than once, and diagnose delayed sends or Inbound Parse endpoints that stop receiving data.6 questions
- Mailbox Provider-specific IncidentsWork provider-specific blocks and deferrals at Gmail, Outlook, Hotmail, Yahoo, AOL and iCloud — telling spam placement, throttling and outright rejection apart — and confirm recovery once a provider reports a fix.10 questions
Email deliverability expert
Wojtek Blazalek
Stuck in an email incident? I help teams get delivery, reputation and auth back on track.
Hands-on deliverability work for teams that send at scale