Incoming mail
You can select the type of format in which you prefer to receive your incoming mail.
Choose Mail, clicking the "Internet-style Mail Options" button, and then clicking the "Incoming Mail" button under "Options for receiving mail."
(Macintosh OS X users: ), clickingIf you read mail through HCL Notes® and a browser or if you usually receive both Notes® and Internet mail, you should choose "Keep in sender's format." This is the recommended and default choice because it ensures that the mail you receive leaves all security information intact. Mail from Notes® users will normally be encrypted with Notes® certificates, and mail from people on the Internet can be secured with Internet certificates.
If you normally check your Notes® mail through an Internet browser, it is recommended that you select "Prefer MIME format" in the "Format preference for incoming mail" list. If enabled, Notes® can use your Internet certificates rather than your Notes® certificates for your mail security. If a person is sending you encrypted mail, then the message is encrypted with your Internet certificate (provided your Internet certificates are accessible from the HCL Domino® Directory). It is recommended that you have an accessible Internet certificate in the Domino® Directory. If you have more than one Internet certificate, open your person record in Edit mode, click the "Examine Internet Certificate(s)" button, select the certificate you want to use, and then click the "Set As Default For Encryption" button.
However, if you normally read your Notes® mail from the Notes® client itself and if you never receive any mail from the Internet, you can select "Prefer Notes® rich text format." "Prefer Notes® rich text format" encourages use of your Notes® certificate for encrypted mail and encourages use of the sender's Notes® certificate when sending you digitally signed mail.