The ramblings of a computer geek
The periodic reset of the KRBTGT password is now recommended by Microsoft to be carried out every 180 days. Resetting the password periodically reduces the risks of a Kerbroasting attack being successful. To ensure the KRBTGT password is fully reset you MUST perform this reset operation twice. And you MUST wait a bare minimum of … Read more
Can you restore a Microsoft Exchange 2016 or 2019 mailbox database to a Microsoft Exchange SE server? The short answer is yes you can, but you must use the Recovery Database approach. Why would you want to? Well, if like us you are moving at pace to Microsoft Exchange SE to ensure you are on … Read more
A quick command to determine where a mailbox has been moved during its lifetime. It is common for a mailbox to have been moved from database to database, and therefore at different points in time been backed up to different databases. When it comes to a need to restore a database, then you’ll need to … Read more
Here’s an interesting one I came across today, there exists a problem whereby replacing a certificate on a Microsoft Exchange 2016 or 2019 won’t work if the Issuer and Subject of the new certificate happen to be the same as the old certificate (you are trying to replace). You’d expect most likely that when you … Read more
What to do when your self-signed certificate for Microsoft Exchange 2016 expires, Microsoft provide some good guidance about this: https://learn.microsoft.com/en-us/exchange/architecture/client-access/renew-certificates?view=exchserver-2019 You might see errors such as this when you’re trying to administer via PowerShell: You’ll have permissions so the error is a red herring, what is actually happening is you’re attempting to perform an operation … Read more
The time of on-premise Microsoft Exchange servers is beginning to draw to a close, although the Microsoft Exchange Server SE will continue, its feature complete essentially as of Exchange Server 2019, although there may be the odd minor changes here and there. Based on that replacing the certificate is a common task, the following instructions … Read more
Microsoft Windows 2016 does not support the newer encryption ciphers used by default by EJBCA (AES256-SHA256), therefore we need to generate a version of the certificate using the earlier encryption cipher type, i.e. TripleDES-SHA1 which is what is supported by the earlier version of Microsoft Windows, namely Server 2016. Check Encryption Ciphers Used Firstly get … Read more
Investigation into the loss of Rich Hybrid features for on-premise mailbox users, from around the beginning of November 2025. Exchange Version Says we need Exchange Server 2016 CU23 with April 2025 HU 15.1.2507.55, we are currently running 15.1.2507.58, so a later version than the minimum requirement, thus we are good on this version. Identified Issue … Read more
The document provides a simple guide to how to install and use the Microsoft Exchange Online PowerShell modules to interact with Microsoft 365 infrastructure for the purposes of administering the Microsoft 365 infrastructure and applications; i.e. how to setup your Developer Machine. You may be able to install modules without administrative rights by adding the … Read more
The document provides a simple guide to how to install and use the Microsoft Graph and Microsoft Exchange Online PowerShell modules to interact with Microsoft 365 infrastructure for the purposes of administering the Microsoft 365 infrastructure and applications; i.e. how to setup your Developer Machine. You may be able to install modules without administrative rights … Read more