While email appears to be seamless and immediate for users, there’s a complex system in place that ensures performance, security, and trust in the inbox. A key component of this system, often misinterpreted, is SMTP throttling. Regardless of whether you’re dispatching transactional emails, marketing blasts, or bulk notifications, SMTP throttling regulates the speed, frequency, and volume of mail your server can transmit before restrictions take effect.
A rigorous DKIM troubleshooting workflow helps you isolate and remediate the exact cause of a DKIM fail before it cascades into deliverability issues or mail server rejection.
College life depends on being online. From registering for classes and submitting assignments to paying bills and staying in touch with friends, nearly everything happens through a screen. That constant connection makes life easier, but it also creates risks many students don’t think about until something goes wrong. Cybersecurity isn’t just an issue for big companies or tech experts. It affects students every day, often in quiet ways that don’t seem serious until accounts are locked, files disappear, or money goes missing.
Email authentication can feel deceptively simple—until SPF records start failing and legitimate messages land in spam. One of the most common and frustrating causes is the SPF 10 DNS lookup limit, a technical restriction that many organizations hit as they add third-party email services.
This is the 4th edition of January, and last week witnessed multiple ups and downs in the cybersecurity ecosystem. Microsoft turned out to be the most mimicked brand in the last quarter of 2025, while experts realized the imminent cyber threat during the Winter Olympics. A West London council was targeted by hackers, leading to a breach of sensitive personal data. Meanwhile, a group of experts has stated that 2026 is going to witness highly sophisticated social engineering tactics over vulnerability-oriented cyberattacks.
Email authentication is fundamental to achieving secure and dependable email delivery, with DKIM being a key factor in verifying the authenticity and integrity of your communications. However, merely implementing DKIM is insufficient — ineffective selector management can compromise security, lead to verification errors, and damage your sender reputation.
The success of email delivery is largely influenced by effective domain authentication, with a crucial aspect often neglected being the SPF void lookup. When an email server assesses a domain’s Sender Policy Framework (SPF) record, it conducts DNS lookups to confirm that the sending source is permitted. If these lookups fail or yield no results, they are categorized as “void lookups,” which can undermine the strength of your domain’s authentication.
Last week was replete with unfortunate phishing mishaps. Here are the top cyber incidents that we have covered for you to keep you updated. While Amazon, the e-commerce giant, is being targeted by phishing actors, left, right, and center, LinkedIn is also becoming a popular playground for cybercrooks. The crypto community is already in shock because of the Ledger customer data breach incident. Meanwhile, a highly sophisticated campaign is targeting the user credentials by impersonating Google Support.
The sophistication of email threats is increasing, complicating the ability of businesses to safeguard their domains and reputation. DMARC XML reports provide essential information regarding entities sending emails on your behalf; however, the raw data can be intricate and challenging to analyze.(more…)
Ensuring your emails land in the inbox rather than the spam folder is essential for effective communication. As phishing threats become more prevalent and email authentication requirements tighten, it’s crucial for organizations to take additional measures to authenticate their messages.
DMARC enforcement best practices: Moving from ‘none’ to ‘reject’
by DuoCircle
It’s 2026, and email-based attacks remain one of the major concerns for organizations. It opens the door to sophisticated attacks such as phishing, brand impersonation, and business email compromise. This means cursory checks are no longer enough.
In the ever-evolving landscape of email security, Sender Policy Framework (SPF) is a cornerstone protocol for authenticating emails, defending against spoofing, and enhancing email deliverability.
This week’s cybersecurity news highlights how trust-based digital systems continue to be exploited across crypto platforms, browser ecosystems, and online marketplaces. Trust Wallet disclosed a major supply-chain attack that led to millions in stolen crypto, while researchers uncovered a long-running browser extension campaign tied to corporate espionage.
Email continues to be an essential tool for business communication, yet it faces significant risks from spoofing and phishing threats. Insights from DMARC testing enable organizations to assess the effectiveness of their email authentication and identify potential weaknesses, positioning DMARC as an essential component in safeguarding both incoming and outgoing communications.
Grasping and analyzing a DMARC report is crucial for safeguarding your domain against phishing and spoofing threats. Such a report provides valuable insights into the status of your email authentication, revealing how well your domain adheres to DMARC, SPF, and DKIM protocols.
How to solve the “550 5.7.0 Local Policy Violation” error
by DuoCircle
Maintaining a decent email deliverability rate is what most organizations struggle with, especially if they send bulk emails. Fixing the problem isn’t even the hardest part; the most difficult thing is identifying the root cause.
In today’s interconnected email ecosystem, ensuring effective email deliverability and robust email security is paramount for organizations and domain owners. The Domain-based Message Authentication Reporting and Conformance (DMARC) framework provides a trusted solution to combat spoofing, phishing, and malicious actors by enabling organizations to implement advanced email authentication protocols.
Cyber incidents this week ranged from large-scale scraping to high-impact software and supply chain risks. An activist group claims to have scraped tens of millions of tracks from a major streaming platform, raising fresh copyright concerns. Separately, a critical n8n flaw could allow code execution on exposed instances. Other reports covered a notarized macOS stealer campaign, a GitLab breach impacting a car maker’s customers, and malicious Chrome extensions abusing proxy access to steal credentials.
![Microsoft Phishing Peak, Winter Games Threats, London Data Breach – Cybersecurity News [January 19, 2025]](https://www.duocircle.com/wp-content/uploads/2026/01/email-smtp-service-7865.jpg)
![Spotify Copyright Scrape, n8n Code Execution, MacSync Stealer Installer – Cybersecurity News [December 22, 2025]](https://www.duocircle.com/wp-content/uploads/2025/12/spf-record-check-7888.jpg)