Encrypting mail

Encrypting outgoing mail ensures that only the recipient of a message can read it while the message is in transit, stored in intermediate mailboxes, or in the recipient's mail file.

Each Notes® client user must encrypt outgoing mail. The administrator cannot encrypt all outgoing mail on a server.

Senders control the choice of MIME format or Notes® format when sending mail directly to the Internet or for messages that are addressed to Internet addresses. Mail recipients control the format of incoming mail in their user preferences. The message format determines the choice of encryption method.

Notes® uses S/MIME encryption for outgoing mail in the following situations:

• The user selects directly to Internet in the Send outgoing mail field in the Mail tab of the current Location document. Mail messages sent from this location use MIME format.
• The user selects MIME format in the Format for messages addressed to Internet addresses field in the Mail tab of the current Location document. Mail messages sent from this location to Internet addresses that cannot be found in Contacts or Domino® Directory use MIME.
• The user enables the field When receiving unencrypted mail, encrypt before storing in your mail file on the Basics tab of the user's Person document. Mail sent to this user use MIME.
• The user creates a message using a form in which the Body field in the form's design has Store contents as HTML and MIME selected in Field Properties. If the recipient can accept either Notes® or MIME format (or if Notes® cannot find a Person document for the recipient), the message uses MIME format.

The sender of an encrypted S/MIME mail message must find an Internet certificate for each intended recipient and a cross-certificate that verifies the Internet certificate. The Internet certificate can be stored in the Domino® Directory, an LDAP directory that is accessible to the sender, or in the sender's Contacts. The cross-certificate must be stored in the sender's Contacts. If a Notes® recipient's Internet certificate is not available to the sender, Notes® attempts to use the recipient's Notes® public key (if available) to encrypt the message.

Some recipients may have dual Internet certificates, meaning one certificate is for encryption and the other is for signatures and SSL. If the recipient uses dual certificates, Notes® extracts the Internet encryption certificate and uses it to encrypt the message.

The sender of an encrypted Notes® mail message must have the public key for each intended recipient. The public key can be stored in the Domino® Directory, in an LDAP directory that is accessible to the sender, or in the sender's Contacts.

If users have Editor access to their Person documents in the Domino® Directory, they can encrypt all incoming mail they receive. Otherwise, the administrator must complete this procedure for them.

Users can encrypt drafts of unsent messages and messages that they save after sending. For unsent mail, the message is encrypted only with the sender's public key. For sent mail, the message is encrypted with the sender's and the recipient's public keys.

Only messages saved after this option is chosen are encrypted. To encrypt previously saved messages, users must open and resave the messages. Encrypting saved mail prevents unauthorized access to messages by other users with unauthorized access to the mail server.