I've had to use Microsoft products (Windows & Office) in an enterprise environment before and, while I'd much prefer to use Thunderbird & GnuPG, Symantec's commercial PGP products in conjunction with Outlook are a good solution for this environment. A centralized server controls configuration and policies and, once up and running, it just works(TM) and, IME/IMO anyways, was a better solution than Outlook + S/MIME.
Of course, this required both sender and receiver to have/use PGP and/or a compatible product.
I've had to use Microsoft products (Windows & Office) in an enterprise environment before and, while I'd much prefer to use Thunderbird & GnuPG, Symantec's commercial PGP products in conjunction with Outlook are a good solution for this environment. A centralized server controls configuration and policies and, once up and running, it just works(TM) and, IME/IMO anyways, was a better solution than Outlook + S/MIME.
Of course, this required both sender and receiver to have/use PGP and/or a compatible product.