DKIM helps email providers verify that a message really came from your domain and that it was not changed while being delivered. At the heart of DKIM is a pair of cryptographic keys called the public key and the private key. These two keys work together to sign emails and prove their authenticity to receiving mail servers.
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.
Financial services organizations are being hit particularly hard. The average cost of a security breach reached $6.08 million in 2024, which is 22% higher than the average cost faced by other industries. Email remains the primary entry point that attackers use.
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.
![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)
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.
What does it really mean to send emails securely?
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.