Once the intermediate certificate has been installed, we can import the certificate for the organization, exported from the Exchange 2007 server earlier.
This is the command we use to import the certificate exported from the Exchange 2007 server:
I use the Get-ExchangeCertificate cmdlet to identity the various certificates (expired and current) that I have on the server and then, locating the one I intend to use (looking at the expiration dates), I enable it with the following cmdlet:
[PS] C:\>Enable-ExchangeCertificate -thumbprint EC523xxxx -Services "IIS,SMTP"
Overwrite the existing default SMTP certificate?
Current certificate: '3366Axxxxxx' (expires 4/28/2019 7:31:12 PM)
Replace it with certificate: 'EC523xxxxx' (expires 3/8/2015 10:32:06 PM)
[Y] Yes [A] Yes to All [N] No [L] No to All [?] Help (default is "Y"): A