Reading Mail with S/MIME content

[Alain Stouder]

Dear All,

The trend towards email SSL signing and encrypting is bringing new 
complexity in the field of reading messages inside Omnis with Mail 
commands and with COM automation through Outlook.

It appears message are contained inside a smime.p7s for signed mail 
and a smime.p7m for encrypted mail.

Certificates from sender and receiver (.cer) are required to be able 
to decode messages and are cached by the operating system to provide 
public/private keys to Apple Mail and Microsoft Outlook that 
automatically read these emails.

But what if the certificate is absent, how to ensure that the message 
will be readable in the future ?

Wondering if anybody has experience with this and willing to share it 
for Windows and Mac platforms ?

Thanks,
Alain