A new report by Avanan shows that the Office 365 cloud-based email filtering service is ineffective against almost one in every three phishing emails. The report found that the Office 365 Exchange Online Protection (EOP) marked 25% of phishing emails as clean, while an additional 5.3% were whitelisted, as a result of which only 69.7% of phishing messages were blocked, with only 20.7% being correctly identified as phishing emails and the remaining 49% being considered spam.

According to the report, 1 out of every 99 emails is a phishing message containing a malicious link or attachment. When it comes to phishing campaigns involving brand impersonation, the two most impersonated brands are Microsoft (43%) and Amazon (38%).

Read more: 25% of Phishing Emails Bypass Office 365 Default Security