HOW TO encrypt and store mail

Hello,

We are looking for a solution to store and encrypt mails.

We need to comply with PCI (Payment Card Industry) standards.
We have Windows 2008 and Exchange 2007 SP2.

So far, we haven't found a way to encrypt and store mail in Exchange.
We'll be encrypting communications with TLS.

Plus, we need to use OE (Outlook Express) so we can use IMAP for
incoming mail and SMTP for outgoing e-mail.

Any ideas/suggestions are more than welcome.

Thank you.


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