Category: Microsoft Defender Advanced Threat Protection

  • Blocking onmicrosoft.com Emails in Exchange Online Protection

    Blocking onmicrosoft.com Emails in Exchange Online Protection

    There is a considerable uptick in emails from the default domain in Microsoft 365 tenants. These emails come from senders @ tenant.onmicrosoft.com and are not your tenant. Microsoft recently announced recipient external sender limits to reduce this, as the default is 10,000 recipients per day, but will get an additional restriction of no more than…

  • SSL Inspection and Microsoft 365

    SSL Inspection and Microsoft 365

    There are a number of features in Microsoft 365 that do not work if SSL Inspection (also known as TLS Interception) is enabled on your device or network provider. You need to disable the listed URLs that Microsoft provides in its documentation. The problem is there is a lot of disconnected documentation! This blog post…

  • Safe Links, Microsoft Teams Rooms or Zoom Rooms, and Preset Security Policies

    Safe Links, Microsoft Teams Rooms or Zoom Rooms, and Preset Security Policies

    Or “How to customize Microsoft 365 Preset Security Policies“! The Preset Security Policies in Microsoft 365 allow you to assign to users, groups or domains the recommend anti-spam, anti-spoofing and anti-malware settings (amongst others). In the Microsoft 365 Security Portal (https://security.microsoft.com) where you set this there appears to be no way to customize these policies…

  • Allowing “Phish” Training Emails in Exchange Online

    With the introduction of “Secure by Default” in Exchange Online, where you used to add IPs and other settings such as allow-lists to allow your phish training emails to get through to your users this will no longer work, and shortly it will no longer work to bypass the Exchange Online filters using mail flow…

  • Blocking Apps With a Low Reputation

    One of the benefits of Microsoft 365 is the interaction across many products and features to create services that otherwise you might not have available to you or need to implement unrelated and unconnected additional software and maybe client agents as well. Recently announced is an interaction between Windows Defender (client AV and other security…