What changed
- 120 individual SMTP error and response pages.
- Searchable encyclopedia directory with provider, category and severity filters.
- Working SMTP Bounce Decoder Lab.
- Machine-readable encyclopedia JSON for future tools and expansion.
- Updated homepage, Labs, Reference, search, sitemap, changelog and release metadata.
Coverage
Generic SMTP and enhanced status codes, authentication, SPF, DKIM, DMARC, DNS, routing, TLS, quota, content, reputation, blocklists and provider-specific patterns for Gmail, Microsoft, Yahoo/AOL, GMX/WEB.DE and Apple iCloud.