MAIL
For more information on this and other mail encryption settings, see the topic Editing the Configuration Settings document for Domino Web Access.
If SSL connection is required for either the client or both the client and server, Domino Web Access users cannot read or send encrypted messages when connected via HTTP. If the user is connected via HTTP, they must switch to HTTPS when accessing the encrypted message on the server. This switch occurs automatically when sending encrypted mail. The user will be prompted to switch when reading encrypted mail.
S/MIME is supported in Domino Web Access. Users can verify an S/MIME signature on a received message. Users who have an X.509 certificate in their mail file-based Notes ID can decrypt received S/MIME messages as well as S/MIME sign messages they send. Outgoing messages can be S/MIME encrypted for recipients who have an X.509 certificate in the Domino Directory or in Domino Web Access contacts. Note that for an X.509 certificate to be used by Domino Web Access, an Internet cross-certificate must be issued from the user's organizational certifier to the certificate authority that issued the X.509 certificate. This Internet cross-certificate must be present in the Domino Directory.
When both Notes and S/MIME sign and encryption are possible, Domino Web Access uses S/MIME sign and encryption by default. This could cause problems in a mixed environment that includes both Domino 7 and pre-Domino 7 servers. Pre-Domino 7 servers do not support S/MIME, so messages sent S/MIME signed and encrypted could not be verified or decrypted. Use the NOTES.INI setting iNotes_wa_SecMailPreferNotes to turn on Notes sign and encryption when both S/MIME and Notes sign and encryption are possible. This setting is not supported offline.
For more information on S/MIME encrypted mail, see the topic Mail Encryption.
Deployment differences between Notes and Domino Web Access