email-deliverability — make mail authenticate and land in the inbox

This skill owns one layer: why mail you already send gets filtered, deferred, or rejected, and the DNS + reputation work that fixes it. It starts where the send technically succeeds but the message never reaches the inbox.

The lever is almost never the sending code. It is three DNS records that must align, a complaint rate you must hold down, and a reputation you build slowly and lose fast. Treat this as ops on a domain, not a code change.

Not this skill