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Practical guidance on SPF, DKIM, DMARC, BIMI, phishing protection, and the parts of email infrastructure that quietly break things. Written by the DuoCircle team for people who run email and want to stop getting paged.
Stay informed on the latest cyber threats, including Oracle zero-days, VPN exploits, ransomware attacks, data breaches, and phishing scams.
Learn effective Mail Server Authentication strategies for high-volume email senders to improve deliverability, prevent spoofing, and strengthen email security.
Explore the pros, cons, and compliance risks of Microsoft 365 tenant to tenant migrations. Learn how teams in regulated industries can protect data integrity.
Learn how to configure SPF, DKIM, and DMARC for Amazon SES to improve email security, prevent spoofing, and boost email deliverability.
Struggling to protect customer emails? Discover how modern SMTP for fintech secures against phishing, enhances deliverability, and safeguards sensitive data.
Avoid these 10 DKIM key rotation checklist mistakes that weaken email security, break authentication, and damage email deliverability rates.
Learn how SPF include mechanisms improve email deliverability, strengthen email security, and support scalable SPF record management.
Stay updated with the latest cybersecurity news: DentaQuest breach, Cisco zero-day, Instagram bug, supply chain attacks, and emerging cyber threats.
Prevent SPF configuration errors with these 11 MSP recommendations to improve email authentication, boost deliverability, and strengthen domain security
Protect your web applications from SQL injection attacks with proven prevention strategies, secure coding practices, input validation, and layered defenses.
Avoid costly security risks during an Office 365 migration solution. Protect sensitive business data with best practices for secure migration.
Review 10 essential DKIM authentication testing reports that help security teams identify misconfigurations, improve deliverability, and stop spoofing.
Cybersecurity News: FBI warns of Silent Ransom attacks, Carnival confirms 6M-record breach, GlobalProtect exploits surge, and AI-powered threats grow.
Learn about major DNS vulnerabilities, security risks, and proven ways to reduce exposure, prevent attacks, and strengthen your domain protection.
Verify Sender Policy Framework compliance using SPF lookup tools to identify record issues, improve email authentication, and enhance deliverability.
Avoid these 15 SPF record validation mistakes that can trigger email delivery failures, authentication issues, spam filtering, and domain reputation damage.
Massive cyberattacks hit GitHub, 7-Eleven, NYC hospitals, and more. Explore the biggest cybersecurity threats and breaches from May 18, 2026.
Prevent business email disruption by fixing invalid DKIM selectors quickly to improve email authentication, deliverability, and domain trust.
Learn the top threats to domain reputation and how to avoid them to keep your email and online presence secure.
Learn the top threats to domain reputation and how to avoid them to keep your email and online presence secure.
Learn what GPS spoofing is, how it manipulates location data, the risks it creates, and the methods used to detect and prevent spoofing attacks.
Machine learning helps detect malicious emails and phishing attacks faster, improving email security and reducing cyber threats.
Fix SPF authentication failures in Microsoft 365 and Exchange Online with 7 quick solutions to improve email delivery, stop spoofing, and protect domains.
Critical cybersecurity threats emerge as Cisco SD-WAN, NGINX, Microsoft Exchange, and PAN-OS flaws face active exploitation worldwide.
Learn about 11 common malware types, how they spread, and the warning signs to help protect your devices and data online.
Testing your SPF configuration before a campaign goes live is a core part of modern email authentication.
A data-driven analysis with 20+ primary-source statistics from Verizon, IBM, SecurityScorecard, the FBI, the World Economic Forum, and others.
A DMARC record generator can simplify the process of creating a DMARC policy, but generating the record is only the first step.
Here’s your weekly roundup of the most important cybersecurity stories from the past week, covering major data breaches, critical vulnerabilities.
Contemporary businesses seldom depend on a singular email setup.
Email continues to be one of the most essential communication channels for businesses—but it’s also one of the most targeted by cyber threats.
A data-driven analysis of 26 primary-source statistics from institutional reports by the World Economic Forum, IBM, Verizon, Cisco, Accenture, ISC2, NIST.
Email authentication serves as the foundation for effective email deliverability.
BIMI confuses buyers because two different vendors handle two different jobs. Here is the clean split between VMC procurement (a Certificate Authority function) and BIMI hosting (what your DMARC reporting tool actually does).
The SPF 10-DNS-lookup limit silently breaks email authentication once you exceed it. Here is how to diagnose a permerror, why even careful organizations end up over the limit, and the fix options that actually work.
Your scan-to-email died after a Microsoft 365 update. Here's why basic auth and SMTP AUTH got disabled, the three options your IT team actually has, and the fastest reliable fix.
Email marketing campaigns have the potential to enhance engagement, boost conversions.
Publishing a DMARC record at p=none is the starting line, not the finish line. Here is what p=none actually does, what it does not, and how to move to enforcement without breaking legitimate mail.
Here’s your weekly roundup of the most significant cybersecurity stories from the past week, covering major data breaches, critical vulnerabilities.
Email is one of the most critical communication channels for SaaS companies.
A data-driven analysis with 20+ statistics from Verizon, IBM, Cisco, KPMG, LayerX, Microsoft, the World Economic Forum, and others.
In today’s digital landscape, especially within hybrid cloud frameworks, email authentication has become increasingly vital.
Why DIY-ing DMARC could cost you more than you think.
Email remains an essential communication tool for businesses, utilized for everything from transactional notifications to marketing initiatives and customer.
A data-driven analysis with 20+ statistics from EasyDMARC, Google, Microsoft, IBM, Verizon, CISA, and the PCI Security Standards Council.
Organizations that send large volumes of emails, including software-as-a-service (SaaS) platforms, marketing automation providers.
A data-driven analysis for security leaders, IT teams, and MSPs, with 20+ primary-source statistics from Microsoft, IBM, FBI IC3, KnowBe4, Verizon, Cisco.
Sri Lanka Cyberattack, SilentGlass Threat Defense, Rituals Data Breach, Cybersecurity News [April 20.
Transitioning from a Windows-based SMTP server to a cloud-hosted solution has evolved beyond simple modernization; it’s now a key strategic initiative aimed at.
Email trust is no longer a background technical detail, it’s the foundation of how brands communicate, protect users.
Why these DKIM record examples matter A well-formed DKIM record is the foundation of email authentication.
UK Cyber Surge, Poland Incident Surge, Japan Shipping Attack, Cybersecurity News [April 13.
When your organization operates at scale, emails don’t go out from one domain; they are sent from marketing platforms, HR systems, finance tools.
Every verified email has an unseen signature that plays a crucial role in establishing trust.
In the fast-moving digital world of today, effective email delivery is essential for businesses that rely on smooth communication and customer interactions.
As email security continues to advance, the inbox serves as a crucial entry point, with DKIM testing playing an essential role in its protection.
Apple Pay Scam, Crypto Fraud Victims, Retirement Phishing Loss, Cybersecurity News [April 06.
How ARC resolves email authentication for forwarded messages.
The Sender Policy Framework is deceptively simple: publish a single SPF record as a TXT record in your domain DNS so receiving systems can check whether a.
Selecting the appropriate hosted SMTP server in 2026 is crucial for getting your emails delivered to the inbox rather than the spam folder.
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