M365 Defender for Business security recommendations

For some time now, I have been using M365 Defender for Business in my small tenant without Intune Management. This allows small networks to be monitored very well via the cloud. At regular intervals, I also look at the “Security recommendations”. During this routine check, however, I was somewhat shocked. After all, no alerts, which …

Exchange Online get default calendar permissions

I frequently receive requests from customers who are dealing with the default sharing settings within the Exchange organization and don’t have a reasonable solution for it. Therefore, I sat down and wrote a small PowerShell script that can initially read the default permissions of all user mailboxes. In this case, default permissions refer to the …

Reminder: Exchange Online changes EWS default behavior

Already in February, Microsoft announced that the control over EWS access would be slightly changed. This change will be implemented for all tenants starting April 2025. Here is the post from the Exchange team: Access to the EWS interface can be controlled in two ways: first at the organizational level and also at the user …

Exchange 2019 CU15 or 2025 H1 Cumulative Update

Yesterday, Microsoft released the latest and likely final major update for Exchange Server 2019. This update includes a range of new features and bug fixes. As always, remember to use the Exchange HealthChecker. Here direct link for downloading: Exchange 2019 CU15 Let’s start with the list of changes: Note on Extended Protection: It cannot be …

IanaTimeZoneMappings.xml invalid Exchange after November 2024v2 SU

Anyone who runs the Exchange Healthchecker again after the November 2024v2 Exchange update sometimes finds an error that is not pretty but also not completely critical. Here, I really wonder where the quality control is for the updates. This error should be quickly noticeable and is also quickly fixed. NOTE: Restarting IIS is required, so clients …