Email rejections can silently undermine your campaigns, even when your content is top-notch. A frequent issue is an inadequately set up SPF record. As email service providers enhance their authentication requirements, a basic SPF configuration isn’t sufficient to ensure your emails land in inboxes or are successfully delivered.
Email spoofing and phishing pose significant risks to businesses, regardless of their size. Implementing a DMARC reject policy is crucial for safeguarding your domain, enhancing email credibility, and making sure only legitimate messages are delivered to inboxes.
![BlackBerry stages epic comeback, OpenAI model faces threats, La Sapienza suffers ransomware – Cybersecurity News [February 2, 2026]](https://www.duocircle.com/wp-content/uploads/2026/02/Weekly-News-Updates.jpg)
Last week was replete with cybersecurity issues, which made it quite chaotic for critical infrastructure like pipeline operators and universities. While one of the biggest European Universities still remains offline following a cyberattack, BlackBerry is eventually making a comeback as a cybersecurity solution. Meanwhile, Conpet, a Romanian oil pipeline operator, was targeted by a group of threat actors. OpenAI is also grabbing attention because of its new model, which is suspected to be full of cybersecurity vulnerabilities.
Many email delivery problems happen not because of spam content, but because of small server configuration mistakes. One common example is the “Reverse DNS Does Not Match the SMTP Banner” error. This happens when the hostname linked to your sending IP address is different from the hostname your mail server introduces during the SMTP connection. Email providers treat this mismatch as a trust warning, which can cause emails to land in spam, get delayed, or even be rejected. To maintain stable email delivery, it is important to understand what this error means, why it appears, and how you can fix it quickly.
SMTP authentication issues can silently hinder email delivery, harm the reputation of the sender, and cause frustration for both teams and recipients when they persist. These problems typically arise from misconfigured credentials or outdated security protocols, often due to preventable oversights in mail server and service configurations.
If not addressed, SPF permerrors can disrupt your email authentication and negatively impact your deliverability. Common issues, such as DNS misconfigurations and syntax errors, can usually be resolved easily if you know what to search for.
Implementing a DMARC policy is essential for administrators of Microsoft 365 and Google Workspace to safeguard their domains against spoofing and phishing attacks, as well as to enhance email deliverability.
![Thread Hijack Phishing, Latin America Cyberattacks, Poland Energy Breach – Cybersecurity News [January 26, 2026]](https://www.duocircle.com/wp-content/uploads/2026/02/spf-flatterning-5203.jpg)
This is the 4th edition of the month. Here are the top cyber incidents that kept cybersecurity experts busy last week. While some threat actors have been using real enterprise email threads to make their phishing campaigns more credible, Latin America is experiencing a huge spike in cyber mishaps.
A disciplined DKIM key rotation program protects DomainKeys Identified Mail at scale without interrupting mail flow or risking broken signatures. The first four steps below establish a zero-downtime foundation by auditing your current posture, setting a selector strategy, creating strong DKIM keys, and publishing the new DKIM record safely.
For many enterprises, SPF failures are not caused by incorrect syntax or missing records. They happen because the SPF record silently exceeds a technical limit that most teams are not actively monitoring: the 10 DNS lookup limit. As organizations scale their email operations, they naturally add more sending tools, vendors, and services. Over time, this creates complex SPF records that appear valid on the surface but fail during real-world evaluation by inbox providers.