Concern about Outlook S/Mime encryption and smartcards

[Sunny]

Hi all,

I am working on implementing PKI at the moment and just wanted to
clarify a point and see if anybody had any ideas..

-Smartcards must be used for storage of user S/Mime certs at my
company.
-The Smartcards we use have a limit of 6 certs that can be stored. (1
Login, 1 Signature leaving 4 spare for encryption/decryption certs)
-We use Outlook 2003

My worry is that after a few years or more likely a series of lost
cards some users may have had to have a number of new encryption certs
issued and we will run out of space on the cards to hold the required
cert history to get at all their encrypted mail history.

I am therefore looking at ways of getting encrypted Outlook messages
updated to the most recent key when a cert expires or is revoked to
avoid the dependence on key history (which of course will still get
backed up).

Will forwarding all the messages to self encrypted with the new key
while having the previous key/s available on the card do the job and
has anyone ever tried to automate such a process with VBA?

thks
S