IPv6 subnets: understanding /48, /56, and /64
Which IPv6 prefix should you use for your network? Detailed comparison of /48, /56, and /64 sizes with a table, decision tree, and real-world examples.
Articles - Page 8
February 2026
Passkeys vs passwords: should you ditch your passwords in 2025?
Google, Apple, and Microsoft are pushing passkeys as the replacement for passwords. But are they ready for widespread use? Technical comparison, benefits, limitations, and transition strategy.
Port 25 blocked: diagnosis and solutions by hosting provider
Port 25 is blocked by most cloud providers and ISPs to fight outbound spam. Here's how to diagnose the block and restore your sending capability.
STARTTLS, SSL/TLS and SMTP: which encryption for your emails?
SSL, TLS, STARTTLS, Implicit TLS, DANE, MTA-STS: email encryption in transit relies on mechanisms that are often confused. This guide clarifies each protocol, explains their vulnerabilities, and shows how to configure robust TLS encryption on Postfix, Exim and Exchange.
SMTP ports explained: 25, 465, 587, 2525, which one should you use?
Port 25, 465, 587, or 2525? Each SMTP port has a specific role. This guide breaks down how each port works, its encryption method, the relevant RFCs, and helps you pick the right port for your use case.
How to test the SMTP connectivity of your MX servers
Your DNS records are perfect, but emails aren't getting through? The problem might be at the transport layer. This guide shows you how to test SMTP connectivity for each MX server, step by step.
Phishing trends 2025-2026: APWG statistics and new techniques
Phishing has evolved: generative AI, malicious QR codes, MFA bypass. Explore the 2025 APWG figures and the techniques redefining the threat landscape in 2026.
Google Safe Browsing, URLhaus, PhishTank, VirusTotal: how threat intelligence databases work
Every day, your browser queries threat intelligence databases to block malicious URLs. Learn how the 4 main databases work and why combining them is essential.