Skip to main content
Phishing 4 min read

Is Your Office 365 Email Solution Prepared For Phishing Threats?

Brad Slavin
Brad Slavin General Manager
Updated June 16, 2025

Quick Answer

Office 365's built-in phishing filters miss enough impersonation attempts and malicious links to leave most organizations exposed. Microsoft's defaults catch known-bad senders, but adversaries are using paypaI vs paypal lookalike domains, freshly registered URLs, and weaponized attachments faster than reputation feeds update. The fix is layered: keep Office 365's native filters, then add real-time link-click rewriting that re-checks every URL against multiple reputation databases on each click (not just at delivery), plus attachment quarantine, message replay, and an authenticated outbound SMTP path for any apps sending on the domain's behalf. Spam and phishing protection from DuoCircle is built for Microsoft 365 and Exchange tenants in this scenario.

phishing

Microsoft® Office 365™ is one of the best choices around when it comes to business email

It offers multiple tools and benefits for not only email, but overall business productivity. While office 365 does offer Phishing protection as an add on feature, for a comprehensive and real time phishing protection a true end-to-end dedicated protection solution is required.

Microsoft Exchange / Outlook running in a traditional on-site environment allows IT departments to invest in and implement anti-phishing strategies in-house, and also mitigate against other threats such as malware, spam, and zero-day attacks. Once the decision is made to migrate to the cloud, the same threats that once were handled in-house become more serious and difficult to manage with Office 365, despite all its strengths in other areas.

DuoCircle offers a solution to phishing threats associated with Office 365

Advanced Threat Defense from DuoCircle offers phishing protection that compliments Office 365’s business productivity features. With DuoCircle, you can have both the benefits of a world-class office productivity coupled with a powerful email solution and the peace of mind that comes with knowing that your organization is protected from all forms of email based attack, including phishing.

The facts about phishing are clear: 91% of phishing attacks are instigated by domain name or display name spoofs in links sent within an email. As an example, the difference between “paypaI” and “paypal” isn’t readily apparent, but in the first example, the last letter is a capital “i.” If the email comes from a source that the user accepts as being PayPal, the link might take them to a site that appears exactly like the real paypal login. Once the user logs in, however, the attacker has the user’s paypal credentials.

phishing

DuoCircle’s phishing and malware protection defends against exactly this sort of threat: every link is checked against multiple URL reputation databases in real time, not only the first time the link is clicked, but every time. If the link is suspicious, a warning is issued to the user that they are headed to an unsafe site.

Link Click Protection is a part of the Advanced Threat Defense Suite. With Advanced Threat Defense, your organization will benefit from:

  • Protection against targeted Office 365 phishing protection attacks such as the including multiple ransomware variants, as well as other phishing companies attacks with Link Click Protection.
  • A Spam Filtering Gateway that filters and sanitizes your email with our commercial grade spam filtering engine, with all the features and protection associated with an enterprise level solution at a fraction of the cost, to detect phishing before it causes any damage.
  • Message Replay that backs up all incoming email for a short time so it can be recovered in the event of data loss or corruption, or server misconfiguration.
  • Backup MX, which stores an unlimited amount of email and attachments on DuoCircle’s servers for up to 30 days, with automatic domain failover in the event of a disaster.
  • Optional Outbound SMTP with DKIM signing to reliably send email from any application or device that can establish a connection and authenticate with an SMTP server.

Advanced Threat Defense: Phishing Protection And More For Office 365

Face it: for all of its productivity benefits for business and its robustness as an email solution, Office 365 is vulnerable to email-based attacks. DuoCircle stands ready to protect your company from phishing, malware, viruses, spam, and data loss with Advanced Threat Defense. The threat of attack isn’t going away, hackers are getting smarter and developing more sophisticated exploits every day. The best time to defend against threats and block phishing emails is before the attack happens.

More information about Advanced Threat Defense with Link Click Protection

Brad Slavin
Brad Slavin

General Manager

General Manager at DuoCircle. Product strategy and commercial lead across the email security portfolio.

Secure your email infrastructure

Protect, authenticate, and deliver. Contact our team to find the right solution.