I use Dumpsec which works pretty good. Here is the link in case you want to take a look. It allows you to find disabled accounts and other info as well like last logon, groups, etc.
To show how to generate a certificate request in Exchange 2013. We show this process by using the Exchange Admin Center.
Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center.
Navigate to the Servers >> Certificates…