Place the cert on the C’ Drive, in the root folder
Open up Exchange Powershell (Run as Administrator) – they run the command below.

Import-ExchangeCertificate -FileData ([Byte[]]$(Get-Content -Path "C:\FILE_LOCATION.cer" -Encoding byte -ReadCount 0)) |Enable-ExchangeCertificate -Services IIS, POP, IMAP

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