Setting up S/MIME to send and receive signed and encrypted email messages

Note:  This feature is for ZCS Network Edition only and is available only in the Advanced Web Client.

If the S/MIME feature is enabled for your account, you can send and receive digitally signed and encrypted messages.

To use S/MIME with the Zimbra Web Client you must have a secure email signing certificate suitable for S/MIME signing and encryption. The certificate with private key must be installed in the local certificate store on Windows computer, Mac OSX computer, or in the browser certificate store if using Firefox. For information about how to install your certificate see the appropriate computer or browser documentation.

To send and receive encrypted and signed messages your public key and recipient's public key must be exchanged. To get a copy of a recipient's public key, you can send a digitally signed message using your certificate to the recipient and request that they send you a digitally signed message in reply. When the message is received, the recipient's certificate is stored in the recipient's contact page in Address Book, or a contact is automatically created.

Note the following differences when working with encrypted messages:

• If you are sharing your Inbox, delegated users cannot read your encrypted messages from their computers. Your private key is required to read encrypted messages.

• You cannot save a draft of a message encrypted.

• You cannot run spell check on encrypted messages.

• You cannot search for text in the body or attachments of an encrypted message.  Only the header information such as sent to or from, date message was sent, or subject can be found in a search.