Office 365 Phishing Protection

Office 365 is a fantastic suite of productivity-enhancing software solutions, but the Office 365 phishing protection capabilities leave a lot to be desired. While the free security offering, Exchange Online Protection (EOP), has sufficiently good spam and phishing email detection capabilities for personal users, businesses should augment EOP with other security solutions.

EOP does a pretty good job at blocking spam emails, with independent tests indicating around 99% of spam emails are blocked, and the false positive rate is also low. This is important as if a lot of genuine emails are falsely flagged as spam, not only will this have a negative impact on productivity, but users will also be fishing around in their quarantine folder and could end up opening emails that have been correctly identified and blocked. EOP will also block 100% of known malware.

One of the main issues is EOP is not capable of blocking malware for which the signature is not known. That means that any new malware variants, which may only differ slightly from previous versions, will not be identified as malicious, as EOP has no behavioral detection capabilities. EOP will block most spam emails, but third-party email security solutions will increase the 99% spam catch rate to more than 99.9% and phishing email detection is simply not good enough for many businesses. If you opt for a third-party email security solution and layer this on top of EOP, you will be able to block more phishing emails, especially the sophisticated phishing attempts that EOP fails to block.

How to Improve Office 365 Phishing Protection

Many security professionals feel a lot more comfortable with having a third-party email security solution in front of Office 365, which adds an extra layer of Office 365 phishing protection. Microsoft does offer a good advanced threat protection solution, Microsoft Defender for Office 365, which incorporates more advanced anti-phishing and anti-malware capabilities, through the safe links and safe attachments features. While the advanced set of features is vastly superior to EOP alone, there are third-party solutions that can increase protection further and have superior phishing and malware detection rates, fewer false positives, greater flexibility, and integration with other security solutions is easier. There are also cost savings to be gained by opting for a third-party Office 365 phishing protection solution.

Alternatives to Microsoft Defender Improving Office 365 Phishing Protection

To help you with your search, we have listed three of the leading email security solutions for improving Office 365 phishing protection. These solutions are layered on top of the EOP solution provided by Microsoft, to add further layers of protection against sophisticated phishing and malware threats.

SpamTitan Email Security

SpamTitan Email Security from TitanHQ incorporates dual anti-virus engines for blocking known malware threats, and a Bitdefender-powered sandbox for behavioral analysis of suspicious attachments that pass the AV controls. The spam detection rate is in excess of 99.9%. Anti-phishing capabilities include greylisting, anti-spoofing, link analysis, DNS authentication, advanced reputation checks, and machine learning algorithms for predicting new phishing threats. The solution scores highly for ease of setup, use, and maintenance, support is very good, and the product is very competitively priced, although the interface could do with some improvement. SpamTitan Plus+ – the latest addition to the product portfolio – has industry-leading phishing URL detection thanks to the inclusion of 100% of all market-leading phishing feeds and 1.6x faster phishing URL detection than the current market leaders. SpamTitan gets a 4.6/5 rating on Gartner Peer Insights for email security.

Mimecast Email Security with Targeted Threat Protection

Mimecast Email Security with Targeted Threat Protection is another popular alternative to Defender for improving Office 365 phishing protection. This is another solution that is quick and easy to implement and is a major improvement on EOP and has an all-important sandboxing feature for behavioral analysis of email attachments for identifying novel malware threats. Integration with Office 365 is good, although one criticism often reported by users is management is a little cumbersome and Mimecast has moved to a paid training subscription model. The overall cost is higher than many alternatives; however, in terms of phishing and malware protection, the product does score very well. Mimecast gets a 4.5/5 rating on Gartner Peer Insights for email security.

Cisco Secure Email

Cisco Secure Email is another excellent option for improving protection against phishing and malware attacks, with good protection against malicious links and attachments, and the ability to block zero-day threats. The solution is highly configurable and fast, and there is an easy-to-use graphical interface, although like many solutions, the interface could do with an upgrade. The solution is fast and detecting and blocking threats and integration with Office 365 is easy. Down points are initial setup can be a little complicated, the cost might be an issue for some businesses – there are cheaper alternatives – and there isn’t a free trial, so it is not possible to try before deciding on a purchase. Cisco gets a 4.4/5 rating on Gartner Peer Insights for email security.


If you use Office 365 for email, you should improve Office 365 phishing protection with either Defender for Office 365 or a third-party anti-phishing solution, as EOP alone will leave you vulnerable to phishing and malware threats. All of the above solutions are highly rated and should be evaluated. Be sure to take advantage of the free trials on offer to put the products to the test.