Blog

Practical, no-fluff guides on email deliverability, blacklists, SPF/DKIM/DMARC, SSL and DNS.

2026-07-20 · Deliverability

Gmail & Yahoo Sender Requirements in 2026: What You Actually Need

The current Gmail and Yahoo bulk-sender rules — SPF, DKIM, DMARC alignment, a sub-0.3% spam rate and one-click unsubscribe — plus what changed in 2025–2026, with sources.

2026-07-20 · Comparison

MxToolbox Alternatives for Blacklist & Deliverability Monitoring (2026)

MxToolbox is the best-known blacklist monitor, but its monitoring starts at $129/mo. An honest, price-and-coverage comparison of the alternatives — with sources.

2026-07-17 · DNS

DNS Hijacking: Real Cases and How to Catch It Early

DNS hijacking rerouted traffic for dozens of governments and companies in the Sea Turtle and DNSpionage campaigns. What happened, how it works, and how change-monitoring catches it — with sources.

2026-07-16 · DNS

Do You Need a CAA Record?

A CAA record tells Certificate Authorities which CAs may issue certificates for your domain. Since 2017, CAs must check it. Whether you need one, and how to set it up — with sources.

2026-07-15 · Blacklists

How Often Should You Check Email Blacklists?

Manual blacklist checks are a snapshot; you can be listed an hour later. Why continuous monitoring beats spot checks, and sensible intervals by sender type — with sources.

2026-07-14 · Registration

Domain Expired? The Grace Period Timeline (and How to Recover It)

After a domain expires it moves through an auto-renew grace period, a 30-day redemption period, then a 5-day pending-delete before it drops. The full ICANN timeline and how to recover — with sources.

2026-07-13 · Email Auth

How to Find Your DKIM Selector

A DKIM selector is the label before ._domainkey in DNS, chosen by your mail provider. Where to find it — in an email header, from provider defaults, or by probing — with sources.

2026-07-12 · Email Auth

How to Check SPF, DKIM and DMARC in One Place

SPF, DKIM and DMARC work as a system — checking one in isolation misses the point. How to check all three together, what a healthy setup looks like, and the order to fix them — with sources.

2026-07-11 · SSL / TLS

SSL Certificate Expired? A Step-by-Step Recovery Checklist

An expired SSL certificate throws a full-page browser warning and blocks your site. A step-by-step checklist to renew, redeploy and prevent it happening again — with sources.

2026-07-10 · Email Auth

DMARC p=none vs quarantine vs reject: Which Policy Should You Use?

DMARC p=none only monitors, p=quarantine sends spoofs to spam, p=reject blocks them. What each does, how to move safely from none to reject, and why none is not a destination — with sources.

2026-07-09 · Email Auth

SPF "Too Many DNS Lookups": Why It Happens and How to Fix It

SPF fails permerror when it needs more than 10 DNS lookups (RFC 7208). Why the limit exists, how includes blow past it, and five ways to get back under — with sources.

2026-07-08 · Blacklists

Why Is My Domain Blacklisted? Causes and How to Get Delisted

Your domain lands on a blacklist when a DNSBL sees spam-like behaviour from its mail IPs. The common causes, how to find which list, and how to get delisted — with sources.