Get-ExchangeCertificate (Get-AuthConfig).CurrentCertificateThumbprint
[PS] C:\Windows\system32>Get-ExchangeCertificate (Get-AuthConfig).CurrentCertificateThumbprint | select Subject, NotAfter, NotBefore Subject NotAfter NotBefore ------- -------- --------- CN=Microsoft Exchange Server Auth Certificate 03.08.2021 09:34:18 03.08.2016 09:34:18