| name | email-deliverability |
| version | 0.1.0 |
| description | Use this skill when optimizing email deliverability, sender reputation, or authentication. Triggers on SPF record setup, DKIM signing configuration, DMARC policy deployment, IP warm-up planning, bounce handling strategy, sender reputation monitoring, inbox placement troubleshooting, email infrastructure hardening, DNS TXT record configuration for email, and diagnosing why emails land in spam. Acts as a senior email infrastructure advisor for engineers and marketers managing transactional or marketing email.
|
| tags | ["email","deliverability","spf","dkim","dmarc","reputation","devops","strategy","marketing"] |
| category | communication |
| recommended_skills | ["email-marketing","absolute-seo","privacy-compliance"] |
| platforms | ["claude-code","gemini-cli","openai-codex","mcp"] |
| license | MIT |
| maintainers | [{"github":"maddhruv"}] |
Key principles
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Authenticate everything, no exceptions - Every sending domain must have
SPF, DKIM, and DMARC configured. Missing any one of these is enough for
major mailbox providers (Gmail, Outlook) to treat your mail as suspicious.
Authentication is table stakes, not a nice-to-have.
-
Reputation is earned slowly and lost instantly - Sender reputation is
built over weeks of consistent, low-complaint sending. A single spam trap
hit or complaint spike can tank your reputation overnight. Treat every send
decision as a reputation decision.
-
Bounces are signals, not noise - Every bounce carries information about
your list health, infrastructure, or content. Hard bounces must be removed
immediately. Soft bounces must be tracked and acted on. Ignoring bounces
is the fastest path to blocklisting.
-
Warm up before you scale up - New IPs and domains have zero reputation.
Mailbox providers throttle unknown senders aggressively. A proper warm-up
plan ramps volume gradually over 2-6 weeks, proving you are a legitimate
sender before asking for high throughput.
-
Monitor continuously, not reactively - By the time users report "emails
aren't arriving," the damage is done. Monitor bounce rates, complaint rates,
and inbox placement proactively. Set alerts on thresholds, not symptoms.
Core concepts
Email deliverability is governed by three layers: authentication (proving
you are who you claim to be), reputation (proving you send mail people
want), and behavior (proving your sending patterns are consistent and
trustworthy).
Authentication uses three DNS-based protocols that work together. SPF
declares which IPs may send on behalf of your domain. DKIM attaches a
cryptographic signature to each message that receivers verify against a public
key in your DNS. DMARC ties SPF and DKIM together with a policy that tells
receivers what to do when authentication fails - and sends you reports about it.
Reputation is a score maintained by each mailbox provider independently.
It is influenced by complaint rates (users clicking "spam"), bounce rates,
spam trap hits, engagement signals (opens, clicks, replies), and sending
volume consistency. There is no single universal reputation score - Gmail,
Outlook, and Yahoo each maintain their own.
Behavior covers sending patterns: volume consistency, warm-up adherence,
list hygiene practices, and how you handle bounces and unsubscribes. Sudden
volume spikes, sending to stale lists, or ignoring unsubscribe requests all
signal spammer behavior to mailbox providers.
Common tasks
