Passkeys Explained: What They Mean for Email Security
Passkeys promise a future without passwords - no more phishing, no more credential stuffing, no more password reuse. But even in a passkey world, email remains the critical weak point. Here is why email security matters more than ever.
Email Authentication in Practice: When SPF, DKIM, and DMARC Pass and When They Fail
You know what SPF, DKIM, and DMARC are. But do you know why forwarded email fails SPF? Why mailing lists break DKIM? Why DMARC can reject legitimate email? Real-world scenarios explained.
How to Show Your Logo Next to Emails in Gmail (BIMI Explained)
BIMI displays your brand logo next to emails in Gmail, Apple Mail, and Yahoo. Here is what it requires and two ways to set it up.
How Spamhaus Detects Spammers: Inside the World's Largest Threat Intelligence Network
Spamhaus is the most influential anti-spam organization on the planet. Their blocklists protect billions of mailboxes and their decisions can cut off entire networks from email delivery. Here is how they actually work, from spam traps to legal battles.
What Happens to Your Email Before It Reaches Your Inbox?
From the moment someone clicks send to the moment it lands in your inbox - the surprisingly complex journey of an email through DNS, SMTP, spam filters, and authentication.
One-Click Unsubscribe - How It Works and Why Not Every Email Has It
Ever wonder why some emails show an unsubscribe button at the top and others do not? Learn how one-click unsubscribe works technically, why Google and Yahoo now require it, and when it is safe to use.
How We Built Contact Categorization (and Why It Changes Filtering)
Every sender is automatically sorted into one of 20 categories based on their domain. This is not just organization - it unlocks category-based filtering that works on emails you have never seen before.
The Complete Guide to Email Deliverability for Small Senders
You send fewer than 5,000 emails a day but messages still land in spam. A practical guide to authentication, reputation, and content for small-volume senders.
How Gmail Detects Spam: An Inside Look at Google's Email Filtering
Gmail processes billions of emails daily with a multi-layered spam detection system. Here is how authentication checks, reputation scoring, machine learning, and user signals work together to filter spam.
DNS for Email: Everything You Need to Know (But Were Afraid to Ask)
MX, SPF, DKIM, DMARC, PTR, BIMI, MTA-STS - a plain-English deep dive into every DNS record that affects email delivery, authentication, and security.
The Problem with TLD Reputation: Why .xyz and .top Domains Get Blocked
Some domain extensions have such a bad reputation that email from them is blocked by default. Which TLDs are affected, why, and how to filter on them.
Spam Filters Explained: How Email Providers Decide What Is Spam
Bayesian classifiers, IP blacklists, authentication checks, and machine learning - how modern spam filters work under the hood, and why they sometimes get it wrong.
