We use a commercially available Document Management System (DMS) which integrates with Microsoft Outlook 2010. This allows users to save important emails in the DMS so that their colleagues have access to them as well.
At the request of a 3rd party, some users have set themselves up with email encryption, having bought certificates from a CA, installed the certificates into Outlook and exchanged public keys with the client. The email encryption itself works fine, except it is causing problems with the DMS.
A key feature of the DMS is an Outlook add-in which gives users the ability to "Send & File" an email in one operation, both sending the email and prompting for a save location in the DMS to which the same email is BCC'd. When attempting to Send & File an encrypted email (essentially sending an encrpted email to the 3rd party and BCC'ing it to the DMS) users get the error message:
Microsoft Outlook had problems encrypting this message because the following recipients had missing or invalid certificates, or conflicting or unsupported encryption capabilities: <email address for the DMS>
Users can work around this problem by sending the email without filing it into the DMS, then manually filing a copy of the sent email as a separate step. When they do so however other users can't open it because it is encrypted.
To be honest this all seems in order. All the systems (Outlook, DMS & the email encryption process) are doing exactly what they have been asked to do. I have limited sympathy with the users who have set themselves up with a technical solution without consulting me first, but I do want to help salvage this if I can. The obvious solution is to rip this out and start again, probably with TLS encryption between the mail servers of my company and the 3rd party. Before I go that far, however:
- Is there a way in Outlook to send a single email to two recipients, one of whom (the 3rd party) gets an encrypted copy and the other (the BCC to the DMS) gets an unencrypted copy?
- Is there a way to have a single email encryption certificate for all users which will allow everyone to open each other's encrypted emails from the DMS?