You can use either Lotus Notes rich text or native Multipurpose Internet Mail Extensions (MIME) to save and send a mail message over the Internet.
MIME preserves many rich-text features when you send messages to non-Notes mail users over the Internet. However, there are some features in Notes that cannot be expressed in MIME, such as hotspots and horizontal rules.
If you see the MIME Save Warning dialog box, the features listed will lose fidelity or disappear when you send or save the message in MIME.
If the message you are sending contains more than one language character set, you may also see the Multilingual MIME Warning dialog box. You can select either Unicode or the best native character set to handle the content of the document.
Tip: To avoid seeing this dialog box, you can set a preference for multilingual MIME messages. For more information, see Specifying multilingual Internet mail formatting.