The Kalenfy blog
Security, in plain English
Guides on SPF · DMARC · DNSSEC & more — then scan your site free
Fixes & troubleshooting
27 June 2026
What Is DNS Propagation? (Why Changes Take Time)
Just changed a DNS record and nothing's happening? That's DNS propagation. Here's what it really is, how long it takes, why TTL matters, and how to check — with a free scan.
DNS & domain security
27 June 2026
What Is an MX Record? (Email Routing Explained)
An MX record tells the world where to deliver email for your domain. Here's how MX records and their priorities work, common mistakes, and how to check yours free.
Guides & checklists
27 June 2026
What Is Clickjacking? (And How to Stop It)
Clickjacking tricks your visitors into clicking something they can't see by hiding your site in an invisible frame. Here's how it works and how to block it. Free check included.
Fixes & troubleshooting
27 June 2026
How to Redirect HTTP to HTTPS (Force HTTPS)
Stop the 'Not secure' warning by forcing every visitor onto HTTPS. Here's how to redirect HTTP to HTTPS on Apache, Nginx and Cloudflare — and lock it in with HSTS. Free check.
Guides & checklists
27 June 2026
What Are HTTP Security Headers? (HSTS, CSP & More)
HTTP security headers tell browsers how to protect your visitors — blocking clickjacking, mixed content and more. Here's what each one does and how to add them. Free scan included.
DNS & domain security
27 June 2026
DNS Records Explained: A, CNAME, MX, TXT & More
A plain-English guide to DNS records — A, AAAA, CNAME, MX, TXT, NS and the security ones (CAA, DNSSEC). What each does, with a free scan to check your domain's setup.
Email authentication
27 June 2026
How to Create a DMARC Record (with Examples)
A plain-English guide to creating a DMARC record: every tag explained, copy-paste examples for starting out, enforcement and parked domains, and a free check of your result.
Guides & checklists
27 June 2026
How to Improve Email Deliverability
Reach the inbox, not spam. A practical guide to email deliverability — authentication, domain reputation, list hygiene and content — starting with a free check of your setup.
Email authentication
27 June 2026
How to Read DMARC Reports (RUA)
DMARC aggregate (RUA) reports arrive as unreadable XML. Here's what's actually in them, how to read the key fields, what to look for, and how to act on what you find.
Fixes & troubleshooting
27 June 2026
SPF ~all vs -all: Soft Fail vs Hard Fail
What's the difference between ~all and -all in an SPF record? Here's soft fail vs hard fail in plain English, which to use, and why the wrong one leaves you spoofable. Free check.