Articles & Guides

Email spoofing prevention: how spoofing works and how to stop it with SPF, DKIM and DMARC together. Real records, dig verification and the p=reject policy.

DKIM setup step by step: generate the key, pick a selector, publish the TXT record in DNS and verify it with dig. Example records and common DKIM mistakes.

SPF too many DNS lookups error: what the 10-lookup limit means and how to fix it. Counting include, mx, a, SPF flattening, macros and checking with dig.

SPF record explained: v=spf1 syntax, include, a, mx, ip4 mechanisms and the ~all vs -all difference. Example records, dig commands and common SPF mistakes.

How to check and get off an email blacklist: Spamhaus, Barracuda, SORBS. dig commands for DNSBL, listing causes and the step-by-step delisting process.

Why your emails land in spam and how to fix it: SPF, DKIM, DMARC, IP reputation, content and blacklists. Step-by-step domain diagnosis and DNS record checks.

Site goes down intermittently and you can't catch it? How to diagnose flaky outages: continuous monitoring, multi-region checks, a health-check script, and API.

Website slow to load? Break it down by phase: DNS, TCP, TTFB, render. Use curl to measure each phase, then a list of causes and fixes to speed your site up.

Website not loading? A 10-step checklist covering DNS, SSL, origin, firewall, and Cloudflare with real curl, dig, and ping commands for fast diagnosis.

Cloudflare Error 1020 Access Denied means a WAF or Firewall Rule blocked the request. How to find the triggered rule, read the logs, and remove the block.