Installing a Certificate on Exchange 2007
Once you have purchased your certificate, and the domains have been validated as under your ownership, you will receive an email containing the certificate.
The certificate file should be copied onto your Exchange 2007 server. It is then installed using the Import-ExchangeCertificate cmdlet.
Note: do NOT use the Certificates snap-in for the MMC to install the certificate. This will not work for Exchange 2007!
In this example, the certificate file is copied to the server as the file c:\\exchange_example_net.crt
Note: If a UCC was purchased, your certificate file will be ORDER_NUMBER.crt, else your certificate file will be the FQDN that you applied for.
Import-ExchangeCertificate -Path c:\\exchange_example_net.crt | Enable-ExchangeCertificate -Services SMTP ; where c:\\exchange_example_net.crt is your certificate that you got from Comodo.
The 'Services' flag sets which services the certificate is enabled for.
Valid options include: SMTP IMAP POP IIS UM
To enable multiple services:
Note: Once you have installed the site certificate you may need to follow the procedure outlined in 'Root and Intermediate Certificate installation via MMC' with the other files that you have been sent in order to complete the installation.