Sometimes Active Directory DNS fails to scavenge and delete old DNS records. You can grab a list of records using PowerShell.
If a user can’t access an application that authenticates with Microsoft Active Directory, it’s helpful to check to see when the user last set their password since the application may be using cached credentials. Here’s how to use PowerShell to get the passwordlastset value.
This Powershell script finds accounts in Active Directory where the password is set to never expire. Also shows the last time the password was set or reset.
This PowerShell script cycles through a list of users (users.txt) and removes them from all mailboxes in Microsoft Exchange.
If you need to find an Active Directory user when all you have is the objectGUID, you can do so with PowerShell.